diff --git a/make/autoconf/basic.m4 b/make/autoconf/basic.m4
index 585575240ea..f574174a12e 100644
--- a/make/autoconf/basic.m4
+++ b/make/autoconf/basic.m4
@@ -76,6 +76,9 @@ AC_DEFUN_ONCE([BASIC_SETUP_PATHS],
   fi
 
   if test "x$OPENJDK_TARGET_OS" = "xwindows"; then
+    if test "x$OPENJDK_TARGET_CPU_BITS" = "x32"; then
+      AC_MSG_ERROR([32-bit Windows builds are not supported])
+    fi
     BASIC_SETUP_PATHS_WINDOWS
   fi
 
diff --git a/make/autoconf/platform.m4 b/make/autoconf/platform.m4
index 9ca808c4c17..3f977058a51 100644
--- a/make/autoconf/platform.m4
+++ b/make/autoconf/platform.m4
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2023, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2024, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -666,14 +666,14 @@ AC_DEFUN([PLATFORM_CHECK_DEPRECATION],
 [
   AC_ARG_ENABLE(deprecated-ports, [AS_HELP_STRING([--enable-deprecated-ports@<:@=yes/no@:>@],
       [Suppress the error when configuring for a deprecated port @<:@no@:>@])])
-  if test "x$OPENJDK_TARGET_OS" = xwindows && test "x$OPENJDK_TARGET_CPU" = xx86; then
-    if test "x$enable_deprecated_ports" = "xyes"; then
-      AC_MSG_WARN([The Windows 32-bit x86 port is deprecated and may be removed in a future release.])
-    else
-      AC_MSG_ERROR(m4_normalize([The Windows 32-bit x86 port is deprecated and may be removed in a future release.
-        Use --enable-deprecated-ports=yes to suppress this error.]))
-    fi
-  fi
+  # if test "x$OPENJDK_TARGET_CPU" = xx86; then
+  #   if test "x$enable_deprecated_ports" = "xyes"; then
+  #     AC_MSG_WARN([The x86 port is deprecated and may be removed in a future release.])
+  #   else
+  #     AC_MSG_ERROR(m4_normalize([The 32-bit x86 port is deprecated and may be removed in a future release.
+  #       Use --enable-deprecated-ports=yes to suppress this error.]))
+  #   fi
+  # fi
 ])
 
 AC_DEFUN_ONCE([PLATFORM_SETUP_OPENJDK_BUILD_OS_VERSION],
diff --git a/make/autoconf/toolchain_microsoft.m4 b/make/autoconf/toolchain_microsoft.m4
index 387e3717718..4f970df7b5f 100644
--- a/make/autoconf/toolchain_microsoft.m4
+++ b/make/autoconf/toolchain_microsoft.m4
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2022, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2024, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -82,9 +82,7 @@ AC_DEFUN([TOOLCHAIN_CHECK_POSSIBLE_VISUAL_STUDIO_ROOT],
       fi
 
       AC_MSG_NOTICE([Found Visual Studio installation at $VS_BASE using $METHOD])
-      if test "x$TARGET_CPU" = xx86; then
-        VCVARSFILES="vcvars32.bat vcvarsamd64_x86.bat"
-      elif test "x$TARGET_CPU" = xx86_64; then
+      if test "x$TARGET_CPU" = xx86_64; then
         VCVARSFILES="vcvars64.bat vcvarsx86_amd64.bat"
       elif test "x$TARGET_CPU" = xaarch64; then
         # for host x86-64, target aarch64
@@ -132,9 +130,7 @@ AC_DEFUN([TOOLCHAIN_CHECK_POSSIBLE_WIN_SDK_ROOT],
       elif test -f "$WIN_SDK_BASE/bin/setenv.cmd"; then
         AC_MSG_NOTICE([Found Windows SDK installation at $WIN_SDK_BASE using $METHOD])
         VS_ENV_CMD="$WIN_SDK_BASE/bin/setenv.cmd"
-        if test "x$TARGET_CPU" = xx86; then
-          VS_ENV_ARGS="/x86"
-        elif test "x$TARGET_CPU" = xx86_64; then
+        if test "x$TARGET_CPU" = xx86_64; then
           VS_ENV_ARGS="/x64"
         elif test "x$TARGET_CPU" = xaarch64; then
           VS_ENV_ARGS="/arm64"
@@ -438,9 +434,7 @@ AC_DEFUN([TOOLCHAIN_CHECK_POSSIBLE_MSVC_DLL],
     # Need to check if the found msvcr is correct architecture
     AC_MSG_CHECKING([found $DLL_NAME architecture])
     MSVC_DLL_FILETYPE=`$FILE -b "$POSSIBLE_MSVC_DLL"`
-    if test "x$OPENJDK_TARGET_CPU" = xx86; then
-      CORRECT_MSVCR_ARCH=386
-    elif test "x$OPENJDK_TARGET_CPU" = xx86_64; then
+    if test "x$OPENJDK_TARGET_CPU" = xx86_64; then
       CORRECT_MSVCR_ARCH=x86-64
     elif test "x$OPENJDK_TARGET_CPU" = xaarch64; then
       # The cygwin 'file' command only returns "PE32+ executable (DLL) (console), for MS Windows",
@@ -466,9 +460,7 @@ AC_DEFUN([TOOLCHAIN_SETUP_MSVC_DLL],
   DLL_HELP="$2"
   MSVC_DLL=
 
-  if test "x$OPENJDK_TARGET_CPU" = xx86; then
-    vs_target_cpu=x86
-  elif test "x$OPENJDK_TARGET_CPU" = xx86_64; then
+  if test "x$OPENJDK_TARGET_CPU" = xx86_64; then
     vs_target_cpu=x64
   elif test "x$OPENJDK_TARGET_CPU" = xaarch64; then
     vs_target_cpu=arm64
@@ -522,18 +514,8 @@ AC_DEFUN([TOOLCHAIN_SETUP_MSVC_DLL],
     # Probe: Search wildly in the VCINSTALLDIR. We've probably lost by now.
     # (This was the original behaviour; kept since it might turn something up)
     if test "x$VCINSTALLDIR" != x; then
-      if test "x$OPENJDK_TARGET_CPU" = xx86; then
-        POSSIBLE_MSVC_DLL=`$FIND "$VCINSTALLDIR" -name $DLL_NAME \
-        | $GREP x86 | $GREP -v ia64 | $GREP -v x64 | $GREP -v arm64 | $HEAD --lines 1`
-        if test "x$POSSIBLE_MSVC_DLL" = x; then
-          # We're grasping at straws now...
-          POSSIBLE_MSVC_DLL=`$FIND "$VCINSTALLDIR" -name $DLL_NAME \
-          | $HEAD --lines 1`
-        fi
-      else
-        POSSIBLE_MSVC_DLL=`$FIND "$VCINSTALLDIR" -name $DLL_NAME \
-        | $GREP x64 | $HEAD --lines 1`
-      fi
+      POSSIBLE_MSVC_DLL=`$FIND "$VCINSTALLDIR" -name $DLL_NAME \
+      | $GREP x64 | $HEAD --lines 1`
 
       TOOLCHAIN_CHECK_POSSIBLE_MSVC_DLL([$DLL_NAME], [$POSSIBLE_MSVC_DLL],
           [search of VCINSTALLDIR])
diff --git a/make/hotspot/gensrc/GensrcAdlc.gmk b/make/hotspot/gensrc/GensrcAdlc.gmk
index ce3f2684026..d43a8b8d3ab 100644
--- a/make/hotspot/gensrc/GensrcAdlc.gmk
+++ b/make/hotspot/gensrc/GensrcAdlc.gmk
@@ -109,9 +109,7 @@ ifeq ($(call check-jvm-feature, compiler2), true)
       ADLCFLAGS += -DR18_RESERVED
     endif
   else ifeq ($(call isTargetOs, windows), true)
-    ifeq ($(call isTargetCpuBits, 64), true)
-      ADLCFLAGS += -D_WIN64=1
-    endif
+    ADLCFLAGS += -D_WIN64=1
     ifeq ($(HOTSPOT_TARGET_CPU_ARCH), aarch64)
       ADLCFLAGS += -DR18_RESERVED
     endif
diff --git a/make/modules/java.desktop/lib/AwtLibraries.gmk b/make/modules/java.desktop/lib/AwtLibraries.gmk
index b2904f961fd..90eda1c4e64 100644
--- a/make/modules/java.desktop/lib/AwtLibraries.gmk
+++ b/make/modules/java.desktop/lib/AwtLibraries.gmk
@@ -85,11 +85,7 @@ LIBAWT_EXTRA_HEADER_DIRS := \
 LIBAWT_CFLAGS := -D__MEDIALIB_OLD_NAMES -D__USE_J2D_NAMES -DMLIB_NO_LIBSUNMATH
 
 ifeq ($(call isTargetOs, windows), true)
-  LIBAWT_CFLAGS += -EHsc -DUNICODE -D_UNICODE
-  ifeq ($(call isTargetCpuBits, 64), true)
-    LIBAWT_CFLAGS += -DMLIB_OS64BIT
-  endif
-
+  LIBAWT_CFLAGS += -EHsc -DUNICODE -D_UNICODE -DMLIB_OS64BIT
   LIBAWT_RCFLAGS ?= -I$(TOPDIR)/src/java.base/windows/native/launcher/icons
   LIBAWT_VERSIONINFO_RESOURCE := \
       $(TOPDIR)/src/$(MODULE)/windows/native/libawt/windows/awt.rc
diff --git a/make/modules/jdk.accessibility/Launcher.gmk b/make/modules/jdk.accessibility/Launcher.gmk
index 2499cf56616..86ad96b3a1e 100644
--- a/make/modules/jdk.accessibility/Launcher.gmk
+++ b/make/modules/jdk.accessibility/Launcher.gmk
@@ -48,63 +48,44 @@ ifeq ($(call isTargetOs, windows), true)
   TARGETS += $(BUILD_JABSWITCH)
 
   ##############################################################################
-  # Setup rules to create 32/64 bit version of jaccessinspector
-  #
-  # Parameter 1 File name suffix
-  # Parameter 2 ACCESSBRIDGE_ARCH_ -D suffix
+  # Build jaccessinspector
   ##############################################################################
-  define SetupInspector
-    $$(eval $$(call SetupJdkExecutable, BUILD_JACCESSINSPECTOR$1, \
-        NAME := jaccessinspector$1, \
-        SRC := jaccessinspector, \
-        EXTRA_SRC := \
-            bridge \
-            common \
-            toolscommon, \
-        EXTRA_HEADER_DIRS := include/bridge, \
-        CFLAGS := -DACCESSBRIDGE_ARCH_$2 -EHsc, \
-        CXXFLAGS := -DACCESSBRIDGE_ARCH_$2 -EHsc, \
-        LDFLAGS_windows := -stack:655360, \
-        LIBS_windows := advapi32.lib user32.lib, \
-        VERSIONINFO_RESOURCE := \
-            $(ACCESSIBILITY_SRCDIR)/jaccessinspector/jaccessinspectorWindow.rc, \
-    ))
 
-    TARGETS += $$(BUILD_JACCESSINSPECTOR$1)
-  endef
+  $(eval $(call SetupJdkExecutable, BUILD_JACCESSINSPECTOR, \
+      NAME := jaccessinspector, \
+      EXTRA_SRC := \
+          bridge \
+          common \
+          toolscommon, \
+      EXTRA_HEADER_DIRS := include/bridge, \
+      CFLAGS := -DACCESSBRIDGE_ARCH_64 -EHsc, \
+      CXXFLAGS := -DACCESSBRIDGE_ARCH_64 -EHsc, \
+      LDFLAGS_windows := -stack:655360, \
+      LIBS_windows := advapi32.lib user32.lib, \
+      VERSIONINFO_RESOURCE := \
+          $(ACCESSIBILITY_SRCDIR)/jaccessinspector/jaccessinspectorWindow.rc, \
+  ))
+
+  TARGETS += $(BUILD_JACCESSINSPECTOR)
 
   ##############################################################################
-  # Setup rules to create 32/64 bit version of jaccesswalker
-  # Parameter 1 File name suffix
-  # Parameter 2 ACCESSBRIDGE_ARCH_ -D suffix
+  # Build jaccesswalker
   ##############################################################################
-  define SetupWalker
-    $$(eval $$(call SetupJdkExecutable, BUILD_JACCESSWALKER$1, \
-        NAME := jaccesswalker$1, \
-        SRC := jaccesswalker, \
-        EXTRA_SRC := \
-            bridge \
-            common \
-            toolscommon, \
-        EXTRA_HEADER_DIRS := include/bridge, \
-        CFLAGS := -DACCESSBRIDGE_ARCH_$2 -EHsc, \
-        CXXFLAGS := -DACCESSBRIDGE_ARCH_$2 -EHsc, \
-        LDFLAGS_windows := -stack:655360, \
-        LIBS_windows := advapi32.lib comctl32.lib gdi32.lib user32.lib, \
-        VERSIONINFO_RESOURCE := \
-            $(ACCESSIBILITY_SRCDIR)/jaccesswalker/jaccesswalkerWindow.rc, \
-    ))
 
-    TARGETS += $$(BUILD_JACCESSWALKER$1)
-  endef
+  $(eval $(call SetupJdkExecutable, BUILD_JACCESSWALKER, \
+      NAME := jaccesswalker, \
+      EXTRA_SRC := \
+          bridge \
+          common \
+          toolscommon, \
+      EXTRA_HEADER_DIRS := include/bridge, \
+      CFLAGS := -DACCESSBRIDGE_ARCH_64 -EHsc, \
+      CXXFLAGS := -DACCESSBRIDGE_ARCH_64 -EHsc, \
+      LDFLAGS_windows := -stack:655360, \
+      LIBS_windows := advapi32.lib comctl32.lib gdi32.lib user32.lib, \
+      VERSIONINFO_RESOURCE := \
+          $(ACCESSIBILITY_SRCDIR)/jaccesswalker/jaccesswalkerWindow.rc, \
+  ))
 
-  ifeq ($(call isTargetCpuBits, 32), true)
-    $(eval $(call SetupInspector,-32,32))
-    $(eval $(call SetupWalker,-32,32))
-    $(eval $(call SetupInspector,,LEGACY))
-    $(eval $(call SetupWalker,,LEGACY))
-  else
-    $(eval $(call SetupInspector,,64))
-    $(eval $(call SetupWalker,,64))
-  endif
+  TARGETS += $(BUILD_JACCESSWALKER)
 endif
diff --git a/make/modules/jdk.accessibility/Lib.gmk b/make/modules/jdk.accessibility/Lib.gmk
index 657eec2ad4e..6a429a56375 100644
--- a/make/modules/jdk.accessibility/Lib.gmk
+++ b/make/modules/jdk.accessibility/Lib.gmk
@@ -31,84 +31,50 @@ ifeq ($(call isTargetOs, windows), true)
   ACCESSIBILITY_SRCDIR := $(TOPDIR)/src/jdk.accessibility/windows/native
 
   ##############################################################################
-  # Setup rules to create 32/64 bit version of javaaccessbridge
-  #
-  # Parameter 1 Suffix
-  # Parameter 2 ACCESSBRIDGE_ARCH_ suffix
+  ## Build libjavaaccessbridge
   ##############################################################################
-  define SetupJavaDLL
-    $(call SetupJdkLibrary, BUILD_LIBJAVAACCESSBRIDGE$1, \
-        NAME := javaaccessbridge$1, \
-        SRC := libjavaaccessbridge, \
-        EXTRA_SRC := common, \
-        OPTIMIZATION := LOW, \
-        DISABLED_WARNINGS_microsoft := 4311 4302 4312, \
-        CXXFLAGS_FILTER_OUT := -MD, \
-        CXXFLAGS := -MT -DACCESSBRIDGE_ARCH_$2, \
-        EXTRA_HEADER_DIRS := \
-            include/bridge \
-            java.desktop:include, \
-        JDK_LIBS := java.desktop:libjawt, \
-        LIBS_windows := advapi32.lib comdlg32.lib gdi32.lib kernel32.lib \
-            odbc32.lib odbccp32.lib ole32.lib oleaut32.lib shell32.lib \
-            user32.lib uuid.lib winspool.lib, \
-        VERSIONINFO_RESOURCE := \
-            $(ACCESSIBILITY_SRCDIR)/common/AccessBridgeStatusWindow.rc, \
-    )
 
-    TARGETS += $$(BUILD_LIBJAVAACCESSBRIDGE$1)
-  endef
+  $(eval $(call SetupJdkLibrary, BUILD_LIBJAVAACCESSBRIDGE, \
+      NAME := javaaccessbridge, \
+      EXTRA_SRC := common, \
+      OPTIMIZATION := LOW, \
+      DISABLED_WARNINGS_microsoft := 4311 4302 4312, \
+      CXXFLAGS_FILTER_OUT := -MD, \
+      CXXFLAGS := -MT -DACCESSBRIDGE_ARCH_64, \
+      EXTRA_HEADER_DIRS := \
+          include/bridge \
+          java.desktop:include, \
+      JDK_LIBS := java.desktop:libjawt, \
+      LIBS_windows := advapi32.lib comdlg32.lib gdi32.lib kernel32.lib \
+          odbc32.lib odbccp32.lib ole32.lib oleaut32.lib shell32.lib \
+          user32.lib uuid.lib winspool.lib, \
+      VERSIONINFO_RESOURCE := \
+          $(ACCESSIBILITY_SRCDIR)/common/AccessBridgeStatusWindow.rc, \
+  ))
+
+  TARGETS += $(BUILD_LIBJAVAACCESSBRIDGE)
 
   ##############################################################################
-  # Setup rules to create 32/64 bit version of windowsaccessbridge
-  #
-  # Parameter 1 Suffix
-  # Parameter 2 ACCESSBRIDGE_ARCH_ suffix
+  ## Build libwindowsaccessbridge
   ##############################################################################
-  define SetupWinDLL
-    $(call SetupJdkLibrary, BUILD_LIBWINDOWSACCESSBRIDGE$1, \
-        NAME := windowsaccessbridge$1, \
-        SRC := libwindowsaccessbridge, \
-        EXTRA_SRC := common, \
-        OPTIMIZATION := LOW, \
-        DISABLED_WARNINGS_microsoft_WinAccessBridge.cpp := 4302 4311, \
-        CXXFLAGS := -DACCESSBRIDGE_ARCH_$2, \
-        EXTRA_HEADER_DIRS := \
-            include/bridge, \
-        LDFLAGS := \
-            -def:$(ACCESSIBILITY_SRCDIR)/libwindowsaccessbridge/WinAccessBridge.DEF, \
-        LIBS_windows := advapi32.lib comdlg32.lib gdi32.lib kernel32.lib \
-            odbc32.lib odbccp32.lib ole32.lib oleaut32.lib shell32.lib \
-            user32.lib uuid.lib winspool.lib, \
-        VERSIONINFO_RESOURCE := \
-            $(ACCESSIBILITY_SRCDIR)/common/AccessBridgeStatusWindow.rc, \
-    )
 
-    TARGETS += $$(BUILD_LIBWINDOWSACCESSBRIDGE$1)
-  endef
+  $(eval $(call SetupJdkLibrary, BUILD_LIBWINDOWSACCESSBRIDGE, \
+      NAME := windowsaccessbridge-64, \
+      SRC := libwindowsaccessbridge, \
+      EXTRA_SRC := common, \
+      OPTIMIZATION := LOW, \
+      DISABLED_WARNINGS_microsoft_WinAccessBridge.cpp := 4302 4311, \
+      CXXFLAGS := -DACCESSBRIDGE_ARCH_64, \
+      EXTRA_HEADER_DIRS := \
+          include/bridge, \
+      LDFLAGS := \
+          -def:$(ACCESSIBILITY_SRCDIR)/libwindowsaccessbridge/WinAccessBridge.DEF, \
+      LIBS_windows := advapi32.lib comdlg32.lib gdi32.lib kernel32.lib \
+          odbc32.lib odbccp32.lib ole32.lib oleaut32.lib shell32.lib \
+          user32.lib uuid.lib winspool.lib, \
+      VERSIONINFO_RESOURCE := \
+          $(ACCESSIBILITY_SRCDIR)/common/AccessBridgeStatusWindow.rc, \
+  ))
 
-  ifeq ($(call isTargetCpuBits, 32), true)
-    ############################################################################
-    # Build libjabsysinfo
-    ############################################################################
-
-    $(eval $(call SetupJdkLibrary, BUILD_LIBJABSYSINFO, \
-        NAME := jabsysinfo, \
-        OPTIMIZATION := LOW, \
-        VERSIONINFO_RESOURCE := \
-            $(ACCESSIBILITY_SRCDIR)/common/AccessBridgeStatusWindow.rc, \
-    )
-
-    TARGETS += $(BUILD_LIBJABSYSINFO)
-  endif
-
-  ifeq ($(call isTargetCpuBits, 32), true)
-    $(eval $(call SetupJavaDLL,-32,32))
-    $(eval $(call SetupJavaDLL,,LEGACY))
-    $(eval $(call SetupWinDLL,-32,32))
-    $(eval $(call SetupWinDLL,,LEGACY))
-  else
-    $(eval $(call SetupJavaDLL,,64))
-    $(eval $(call SetupWinDLL,-64,64))
-  endif
+  TARGETS += $(BUILD_LIBWINDOWSACCESSBRIDGE)
 endif
diff --git a/make/scripts/compare.sh b/make/scripts/compare.sh
index e81c460225c..cc2f4adf2ed 100644
--- a/make/scripts/compare.sh
+++ b/make/scripts/compare.sh
@@ -76,26 +76,13 @@ fi
 # disassembly, such as hard-coded addresses, to be able to catch "actual" differences.
 
 if [ "$OPENJDK_TARGET_OS" = "windows" ]; then
-  if [ "$OPENJDK_TARGET_CPU" = "x86" ]; then
-    DIS_DIFF_FILTER="$SED -r \
-        -e 's/^  [0-9A-F]{16}: //' \
-        -e 's/^  [0-9A-F]{8}: /  <ADDR>: /' \
-        -e 's/(offset \?\?)_C@_.*/\1<SYM>/' \
-        -e 's/[@?][A-Za-z0-9_]{1,25}/<SYM>/' \
-        -e 's/([-,+])[0-9A-F]{2,16}/\1<HEXSTR>/g' \
-        -e 's/\[[0-9A-F]{4,16}h\]/[<HEXSTR>]/' \
-        -e 's/: ([a-z]{2}[a-z ]{2})        [0-9A-F]{2,16}h?$/: \1        <HEXSTR>/' \
-        -e 's/_20[0-9]{2}_[0-1][0-9]_[0-9]{2}/_<DATE>/' \
-        "
-  elif [ "$OPENJDK_TARGET_CPU" = "x86_64" ]; then
-    DIS_DIFF_FILTER="$SED -r \
-        -e 's/^  [0-9A-F]{16}: //' \
-        -e 's/\[[0-9A-F]{4,16}h\]/[<HEXSTR>]/' \
-        -e 's/([,+])[0-9A-F]{2,16}h/\1<HEXSTR>/' \
-        -e 's/([a-z]{2}[a-z ]{2})        [0-9A-F]{4,16}$/\1        <HEXSTR>/' \
-        -e 's/\[\?\?_C@_.*/[<SYM>]/' \
-        "
-  fi
+  DIS_DIFF_FILTER="$SED -r \
+      -e 's/^  [0-9A-F]{16}: //' \
+      -e 's/\[[0-9A-F]{4,16}h\]/[<HEXSTR>]/' \
+      -e 's/([,+])[0-9A-F]{2,16}h/\1<HEXSTR>/' \
+      -e 's/([a-z]{2}[a-z ]{2})        [0-9A-F]{4,16}$/\1        <HEXSTR>/' \
+      -e 's/\[\?\?_C@_.*/[<SYM>]/' \
+      "
 elif [ "$OPENJDK_TARGET_OS" = "macosx" ]; then
   DIS_DIFF_FILTER="$SED \
       -e 's/0x[0-9a-f]\{3,16\}/<HEXSTR>/g' -e 's/^[0-9a-f]\{12,20\}/<ADDR>/' \
@@ -1467,11 +1454,7 @@ if [ "$SKIP_DEFAULT" != "true" ]; then
         OTHER_SEC_BIN="$OTHER_SEC_DIR/sec-bin.zip"
         THIS_SEC_BIN="$THIS_SEC_DIR/sec-bin.zip"
         if [ "$OPENJDK_TARGET_OS" = "windows" ]; then
-            if [ "$OPENJDK_TARGET_CPU" = "x86_64" ]; then
-                JGSS_WINDOWS_BIN="jgss-windows-x64-bin.zip"
-            else
-                JGSS_WINDOWS_BIN="jgss-windows-i586-bin.zip"
-            fi
+            JGSS_WINDOWS_BIN="jgss-windows-x64-bin.zip"
             OTHER_SEC_WINDOWS_BIN="$OTHER_SEC_DIR/sec-windows-bin.zip"
             OTHER_JGSS_WINDOWS_BIN="$OTHER_SEC_DIR/$JGSS_WINDOWS_BIN"
             THIS_SEC_WINDOWS_BIN="$THIS_SEC_DIR/sec-windows-bin.zip"
diff --git a/src/hotspot/cpu/x86/jniFastGetField_x86_32.cpp b/src/hotspot/cpu/x86/jniFastGetField_x86_32.cpp
index 52e4388c5d2..12336289412 100644
--- a/src/hotspot/cpu/x86/jniFastGetField_x86_32.cpp
+++ b/src/hotspot/cpu/x86/jniFastGetField_x86_32.cpp
@@ -36,17 +36,6 @@
 
 #define BUFFER_SIZE 30
 
-#ifdef _WINDOWS
-GetBooleanField_t JNI_FastGetField::jni_fast_GetBooleanField_fp;
-GetByteField_t    JNI_FastGetField::jni_fast_GetByteField_fp;
-GetCharField_t    JNI_FastGetField::jni_fast_GetCharField_fp;
-GetShortField_t   JNI_FastGetField::jni_fast_GetShortField_fp;
-GetIntField_t     JNI_FastGetField::jni_fast_GetIntField_fp;
-GetLongField_t    JNI_FastGetField::jni_fast_GetLongField_fp;
-GetFloatField_t   JNI_FastGetField::jni_fast_GetFloatField_fp;
-GetDoubleField_t  JNI_FastGetField::jni_fast_GetDoubleField_fp;
-#endif
-
 // Instead of issuing lfence for LoadLoad barrier, we create data dependency
 // between loads, which is much more efficient than lfence.
 
@@ -119,12 +108,7 @@ address JNI_FastGetField::generate_fast_get_int_field0(BasicType type) {
   // ca1 is data dependent on rax,.
   __ jcc (Assembler::notEqual, slow);
 
-#ifndef _WINDOWS
   __ ret (0);
-#else
-  // __stdcall calling convention
-  __ ret (3*wordSize);
-#endif
 
   slowcase_entry_pclist[count++] = __ pc();
   __ bind (slow);
@@ -142,18 +126,7 @@ address JNI_FastGetField::generate_fast_get_int_field0(BasicType type) {
 
   __ flush ();
 
-#ifndef _WINDOWS
   return fast_entry;
-#else
-  switch (type) {
-  case T_BOOLEAN: jni_fast_GetBooleanField_fp = (GetBooleanField_t) fast_entry; break;
-  case T_BYTE:    jni_fast_GetByteField_fp    = (GetByteField_t)    fast_entry; break;
-  case T_CHAR:    jni_fast_GetCharField_fp    = (GetCharField_t)    fast_entry; break;
-  case T_SHORT:   jni_fast_GetShortField_fp   = (GetShortField_t)   fast_entry; break;
-  case T_INT:     jni_fast_GetIntField_fp     = (GetIntField_t)     fast_entry; break;
-  }
-  return os::win32::fast_jni_accessor_wrapper(type);
-#endif
 }
 
 address JNI_FastGetField::generate_fast_get_boolean_field() {
@@ -238,12 +211,7 @@ address JNI_FastGetField::generate_fast_get_long_field() {
 
   __ pop (rsi);
 
-#ifndef _WINDOWS
   __ ret (0);
-#else
-  // __stdcall calling convention
-  __ ret (3*wordSize);
-#endif
 
   slowcase_entry_pclist[count-1] = __ pc();
   slowcase_entry_pclist[count++] = __ pc();
@@ -255,12 +223,7 @@ address JNI_FastGetField::generate_fast_get_long_field() {
 
   __ flush ();
 
-#ifndef _WINDOWS
   return fast_entry;
-#else
-  jni_fast_GetLongField_fp = (GetLongField_t) fast_entry;
-  return os::win32::fast_jni_accessor_wrapper(T_LONG);
-#endif
 }
 
 address JNI_FastGetField::generate_fast_get_float_field0(BasicType type) {
@@ -330,12 +293,7 @@ address JNI_FastGetField::generate_fast_get_float_field0(BasicType type) {
   // access.
   __ jcc (Assembler::notEqual, slow_with_pop);
 
-#ifndef _WINDOWS
   __ ret (0);
-#else
-  // __stdcall calling convention
-  __ ret (3*wordSize);
-#endif
 
   __ bind (slow_with_pop);
   // invalid load. pop FPU stack.
@@ -354,15 +312,7 @@ address JNI_FastGetField::generate_fast_get_float_field0(BasicType type) {
 
   __ flush ();
 
-#ifndef _WINDOWS
   return fast_entry;
-#else
-  switch (type) {
-  case T_FLOAT:  jni_fast_GetFloatField_fp  = (GetFloatField_t)  fast_entry; break;
-  case T_DOUBLE: jni_fast_GetDoubleField_fp = (GetDoubleField_t) fast_entry; break;
-  }
-  return os::win32::fast_jni_accessor_wrapper(type);
-#endif
 }
 
 address JNI_FastGetField::generate_fast_get_float_field() {
diff --git a/src/hotspot/cpu/x86/macroAssembler_x86.cpp b/src/hotspot/cpu/x86/macroAssembler_x86.cpp
index 9854aa5e55a..08e089455f2 100644
--- a/src/hotspot/cpu/x86/macroAssembler_x86.cpp
+++ b/src/hotspot/cpu/x86/macroAssembler_x86.cpp
@@ -4115,7 +4115,7 @@ RegSet MacroAssembler::call_clobbered_gp_registers() {
 
 XMMRegSet MacroAssembler::call_clobbered_xmm_registers() {
   int num_xmm_registers = XMMRegister::available_xmm_registers();
-#if defined(_WINDOWS) && defined(_LP64)
+#if defined(_WINDOWS)
   XMMRegSet result = XMMRegSet::range(xmm0, xmm5);
   if (num_xmm_registers > 16) {
      result += XMMRegSet::range(xmm16, as_XMMRegister(num_xmm_registers - 1));
@@ -10624,10 +10624,6 @@ Assembler::Condition MacroAssembler::negate_condition(Assembler::Condition cond)
   ShouldNotReachHere(); return Assembler::overflow;
 }
 
-// 32-bit Windows has its own fast-path implementation
-// of get_thread
-#if !defined(WIN32) || defined(_LP64)
-
 // This is simply a call to Thread::current()
 void MacroAssembler::get_thread(Register thread) {
   if (thread != rax) {
@@ -10662,9 +10658,6 @@ void MacroAssembler::get_thread(Register thread) {
   }
 }
 
-
-#endif // !WIN32 || _LP64
-
 void MacroAssembler::check_stack_alignment(Register sp, const char* msg, unsigned bias, Register tmp) {
   Label L_stack_ok;
   if (bias == 0) {
diff --git a/src/hotspot/cpu/x86/vm_version_x86.cpp b/src/hotspot/cpu/x86/vm_version_x86.cpp
index f8c5de551cd..688cd4fa5a6 100644
--- a/src/hotspot/cpu/x86/vm_version_x86.cpp
+++ b/src/hotspot/cpu/x86/vm_version_x86.cpp
@@ -517,12 +517,10 @@ class VM_Version_StubGenerator: public StubCodeGenerator {
       // https://msdn.microsoft.com/en-us/library/9z1stfyw.aspx
       __ subptr(rsp, 64);
       __ evmovdqul(Address(rsp, 0), xmm7, Assembler::AVX_512bit);
-#ifdef _LP64
       __ subptr(rsp, 64);
       __ evmovdqul(Address(rsp, 0), xmm8, Assembler::AVX_512bit);
       __ subptr(rsp, 64);
       __ evmovdqul(Address(rsp, 0), xmm31, Assembler::AVX_512bit);
-#endif // _LP64
 #endif // _WINDOWS
 
       // load value into all 64 bytes of zmm7 register
@@ -546,12 +544,10 @@ class VM_Version_StubGenerator: public StubCodeGenerator {
 #ifdef _WINDOWS
     __ subptr(rsp, 32);
     __ vmovdqu(Address(rsp, 0), xmm7);
-#ifdef _LP64
     __ subptr(rsp, 32);
     __ vmovdqu(Address(rsp, 0), xmm8);
     __ subptr(rsp, 32);
     __ vmovdqu(Address(rsp, 0), xmm15);
-#endif // _LP64
 #endif // _WINDOWS
 
     // load value into all 32 bytes of ymm7 register
@@ -611,12 +607,10 @@ class VM_Version_StubGenerator: public StubCodeGenerator {
 #endif
 
 #ifdef _WINDOWS
-#ifdef _LP64
       __ evmovdqul(xmm31, Address(rsp, 0), Assembler::AVX_512bit);
       __ addptr(rsp, 64);
       __ evmovdqul(xmm8, Address(rsp, 0), Assembler::AVX_512bit);
       __ addptr(rsp, 64);
-#endif // _LP64
       __ evmovdqul(xmm7, Address(rsp, 0), Assembler::AVX_512bit);
       __ addptr(rsp, 64);
 #endif // _WINDOWS
@@ -641,12 +635,10 @@ class VM_Version_StubGenerator: public StubCodeGenerator {
 #endif
 
 #ifdef _WINDOWS
-#ifdef _LP64
     __ vmovdqu(xmm15, Address(rsp, 0));
     __ addptr(rsp, 32);
     __ vmovdqu(xmm8, Address(rsp, 0));
     __ addptr(rsp, 32);
-#endif // _LP64
     __ vmovdqu(xmm7, Address(rsp, 0));
     __ addptr(rsp, 32);
 #endif // _WINDOWS
diff --git a/src/hotspot/os/posix/include/jvm_md.h b/src/hotspot/os/posix/include/jvm_md.h
index 2c8ebe06d70..e550ecbb000 100644
--- a/src/hotspot/os/posix/include/jvm_md.h
+++ b/src/hotspot/os/posix/include/jvm_md.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -37,13 +37,6 @@
 #include <stddef.h>             /* For ptrdiff_t */
 #include <stdint.h>             /* For uintptr_t */
 
-#define JNI_ONLOAD_SYMBOLS   {"JNI_OnLoad"}
-#define JNI_ONUNLOAD_SYMBOLS {"JNI_OnUnload"}
-#define JVM_ONLOAD_SYMBOLS      {"JVM_OnLoad"}
-#define AGENT_ONLOAD_SYMBOLS    {"Agent_OnLoad"}
-#define AGENT_ONUNLOAD_SYMBOLS  {"Agent_OnUnload"}
-#define AGENT_ONATTACH_SYMBOLS  {"Agent_OnAttach"}
-
 #define JNI_LIB_PREFIX "lib"
 #ifdef __APPLE__
 #define JNI_LIB_SUFFIX ".dylib"
diff --git a/src/hotspot/os/posix/os_posix.cpp b/src/hotspot/os/posix/os_posix.cpp
index df11832ae95..72330190b53 100644
--- a/src/hotspot/os/posix/os_posix.cpp
+++ b/src/hotspot/os/posix/os_posix.cpp
@@ -696,14 +696,6 @@ void os::print_active_locale(outputStream* st) {
   }
 }
 
-void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
-  // no prefix required
-}
-
-void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
-  // no suffix required
-}
-
 bool os::get_host_name(char* buf, size_t buflen) {
   struct utsname name;
   int retcode = uname(&name);
diff --git a/src/hotspot/os/windows/include/jvm_md.h b/src/hotspot/os/windows/include/jvm_md.h
index 4baba320855..a0e44a45613 100644
--- a/src/hotspot/os/windows/include/jvm_md.h
+++ b/src/hotspot/os/windows/include/jvm_md.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2008, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -39,13 +39,6 @@
 
 typedef int socklen_t;
 
-#define JNI_ONLOAD_SYMBOLS   {"_JNI_OnLoad@8", "JNI_OnLoad"}
-#define JNI_ONUNLOAD_SYMBOLS {"_JNI_OnUnload@8", "JNI_OnUnload"}
-#define JVM_ONLOAD_SYMBOLS      {"_JVM_OnLoad@12", "JVM_OnLoad"}
-#define AGENT_ONLOAD_SYMBOLS    {"_Agent_OnLoad@12", "Agent_OnLoad"}
-#define AGENT_ONUNLOAD_SYMBOLS  {"_Agent_OnUnload@4", "Agent_OnUnload"}
-#define AGENT_ONATTACH_SYMBOLS  {"_Agent_OnAttach@12", "Agent_OnAttach"}
-
 #define JNI_LIB_PREFIX ""
 #define JNI_LIB_SUFFIX ".dll"
 
diff --git a/src/hotspot/os/windows/os_windows.cpp b/src/hotspot/os/windows/os_windows.cpp
index 40a022bbc17..9d514e584a4 100644
--- a/src/hotspot/os/windows/os_windows.cpp
+++ b/src/hotspot/os/windows/os_windows.cpp
@@ -133,7 +133,7 @@ static FILETIME process_kernel_time;
 #elif defined(_M_AMD64)
   #define __CPU__ amd64
 #else
-  #define __CPU__ i486
+  #error "Unknown CPU"
 #endif
 
 #if defined(USE_VECTORED_EXCEPTION_HANDLING)
@@ -282,11 +282,6 @@ void os::run_periodic_checks(outputStream* st) {
   return;
 }
 
-#ifndef _WIN64
-// previous UnhandledExceptionFilter, if there is one
-static LPTOP_LEVEL_EXCEPTION_FILTER prev_uef_handler = nullptr;
-#endif
-
 static LONG WINAPI Uncaught_Exception_Handler(struct _EXCEPTION_POINTERS* exceptionInfo);
 
 void os::init_system_properties_values() {
@@ -399,11 +394,6 @@ void os::init_system_properties_values() {
   #undef BIN_DIR
   #undef PACKAGE_DIR
 
-#ifndef _WIN64
-  // set our UnhandledExceptionFilter and save any previous one
-  prev_uef_handler = SetUnhandledExceptionFilter(Uncaught_Exception_Handler);
-#endif
-
   // Done
   return;
 }
@@ -517,7 +507,7 @@ LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo);
 
 // Thread start routine for all newly created threads.
 // Called with the associated Thread* as the argument.
-static unsigned __stdcall thread_native_entry(void* t) {
+static unsigned thread_native_entry(void* t) {
   Thread* thread = static_cast<Thread*>(t);
 
   thread->record_stack_base_and_size();
@@ -876,14 +866,8 @@ bool os::has_allocatable_memory_limit(size_t* limit) {
   MEMORYSTATUSEX ms;
   ms.dwLength = sizeof(ms);
   GlobalMemoryStatusEx(&ms);
-#ifdef _LP64
   *limit = (size_t)ms.ullAvailVirtual;
   return true;
-#else
-  // Limit to 1400m because of the 2gb address space wall
-  *limit = MIN2((size_t)1400*M, (size_t)ms.ullAvailVirtual);
-  return true;
-#endif
 }
 
 int os::active_processor_count() {
@@ -1549,7 +1533,7 @@ void os::prepare_native_symbols() {
 
 //-----------------------------------------------------------
 // Helper functions for fatal error handler
-#ifdef _WIN64
+
 // Helper routine which returns true if address in
 // within the NTDLL address space.
 //
@@ -1571,7 +1555,6 @@ static bool _addr_in_ntdll(address addr) {
     return false;
   }
 }
-#endif
 
 struct _modinfo {
   address addr;
@@ -1749,7 +1732,6 @@ void * os::dll_load(const char *name, char *ebuf, int ebuflen) {
   } arch_t;
 
   static const arch_t arch_array[] = {
-    {IMAGE_FILE_MACHINE_I386,      (char*)"IA 32"},
     {IMAGE_FILE_MACHINE_AMD64,     (char*)"AMD 64"},
     {IMAGE_FILE_MACHINE_ARM64,     (char*)"ARM 64"}
   };
@@ -1757,11 +1739,9 @@ void * os::dll_load(const char *name, char *ebuf, int ebuflen) {
   static const uint16_t running_arch = IMAGE_FILE_MACHINE_ARM64;
 #elif (defined _M_AMD64)
   static const uint16_t running_arch = IMAGE_FILE_MACHINE_AMD64;
-#elif (defined _M_IX86)
-  static const uint16_t running_arch = IMAGE_FILE_MACHINE_I386;
 #else
   #error Method os::dll_load requires that one of following \
-         is defined :_M_AMD64 or _M_IX86 or _M_ARM64
+         is defined :_M_AMD64 or _M_ARM64
 #endif
 
 
@@ -2101,13 +2081,6 @@ void os::print_memory_info(outputStream* st) {
              (int64_t) ms.ullTotalPageFile >> 20);
     st->print("(AvailPageFile size " INT64_FORMAT "M)",
              (int64_t) ms.ullAvailPageFile >> 20);
-
-    // on 32bit Total/AvailVirtual are interesting (show us how close we get to 2-4 GB per process borders)
-#if defined(_M_IX86)
-    st->print(", user-mode portion of virtual address-space " INT64_FORMAT "M ",
-             (int64_t) ms.ullTotalVirtual >> 20);
-    st->print("(" INT64_FORMAT "M free)", (int64_t) ms.ullAvailVirtual >> 20);
-#endif
   } else {
     st->print(", GlobalMemoryStatusEx did not succeed so we miss some memory values.");
   }
@@ -2228,19 +2201,6 @@ void os::jvm_path(char *buf, jint buflen) {
 }
 
 
-void os::print_jni_name_prefix_on(outputStream* st, int args_size) {
-#ifndef _WIN64
-  st->print("_");
-#endif
-}
-
-
-void os::print_jni_name_suffix_on(outputStream* st, int args_size) {
-#ifndef _WIN64
-  st->print("@%d", args_size  * sizeof(int));
-#endif
-}
-
 // This method is a copy of JDK's sysGetLastErrorString
 // from src/windows/hpi/src/system_md.c
 
@@ -2465,8 +2425,6 @@ LONG Handle_Exception(struct _EXCEPTION_POINTERS* exceptionInfo,
   #define PC_NAME Pc
 #elif defined(_M_AMD64)
   #define PC_NAME Rip
-#elif defined(_M_IX86)
-  #define PC_NAME Eip
 #else
   #error unknown architecture
 #endif
@@ -2590,21 +2548,12 @@ LONG Handle_IDiv_Exception(struct _EXCEPTION_POINTERS* exceptionInfo) {
   ctx->Rdx = (DWORD)0;             // remainder
   // Continue the execution
 #else
-  PCONTEXT ctx = exceptionInfo->ContextRecord;
-  address pc = (address)ctx->Eip;
-  guarantee(pc[0] == 0xF7, "not an idiv opcode(0xF7), the actual value = 0x%x", pc[1]);
-  guarantee((pc[1] & ~0x7) == 0xF8, "cannot handle non-register operands, the actual value = 0x%x", pc[1]);
-  guarantee(ctx->Eax == min_jint, "unexpected idiv exception, the actual value = %d while the expected is %d", ctx->Eax, min_jint);
-  // set correct result values and continue after idiv instruction
-  ctx->Eip = (DWORD)pc + 2;        // idiv reg, reg  is 2 bytes
-  ctx->Eax = (DWORD)min_jint;      // result
-  ctx->Edx = (DWORD)0;             // remainder
-  // Continue the execution
+  #error unknown architecture
 #endif
   return EXCEPTION_CONTINUE_EXECUTION;
 }
 
-#if defined(_M_AMD64) || defined(_M_IX86)
+#if defined(_M_AMD64)
 //-----------------------------------------------------------------------------
 static bool handle_FLT_exception(struct _EXCEPTION_POINTERS* exceptionInfo) {
   // handle exception caused by native method modifying control word
@@ -2619,16 +2568,6 @@ static bool handle_FLT_exception(struct _EXCEPTION_POINTERS* exceptionInfo) {
   case EXCEPTION_FLT_STACK_CHECK:
   case EXCEPTION_FLT_UNDERFLOW: {
     PCONTEXT ctx = exceptionInfo->ContextRecord;
-#ifndef  _WIN64
-    jint fp_control_word = (* (jint*) StubRoutines::x86::addr_fpu_cntrl_wrd_std());
-    if (fp_control_word != ctx->FloatSave.ControlWord) {
-      // Restore FPCW and mask out FLT exceptions
-      ctx->FloatSave.ControlWord = fp_control_word | 0xffffffc0;
-      // Mask out pending FLT exceptions
-      ctx->FloatSave.StatusWord &=  0xffffff00;
-      return true;
-    }
-#else // !_WIN64
     // On Windows, the mxcsr control bits are non-volatile across calls
     // See also CR 6192333
     //
@@ -2639,7 +2578,6 @@ static bool handle_FLT_exception(struct _EXCEPTION_POINTERS* exceptionInfo) {
       ctx->MxCsr = MxCsr;
       return true;
     }
-#endif // !_WIN64
   }
   }
 
@@ -2647,23 +2585,6 @@ static bool handle_FLT_exception(struct _EXCEPTION_POINTERS* exceptionInfo) {
 }
 #endif
 
-#ifndef _WIN64
-static LONG WINAPI Uncaught_Exception_Handler(struct _EXCEPTION_POINTERS* exceptionInfo) {
-  if (handle_FLT_exception(exceptionInfo)) {
-    return EXCEPTION_CONTINUE_EXECUTION;
-  }
-
-  // we only override this on 32 bits, so only check it there
-  if (prev_uef_handler != nullptr) {
-    // We didn't handle this exception so pass it to the previous
-    // UnhandledExceptionFilter.
-    return (prev_uef_handler)(exceptionInfo);
-  }
-
-  return EXCEPTION_CONTINUE_SEARCH;
-}
-#endif
-
 static inline void report_error(Thread* t, DWORD exception_code,
                                 address addr, void* siginfo, void* context) {
   VMError::report_and_die(t, exception_code, addr, siginfo, context);
@@ -2683,98 +2604,18 @@ LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
 #elif defined(_M_AMD64)
   address pc = (address) exceptionInfo->ContextRecord->Rip;
 #else
-  address pc = (address) exceptionInfo->ContextRecord->Eip;
+  #error unknown architecture
 #endif
   Thread* t = Thread::current_or_null_safe();
 
-#ifndef _WIN64
-  // Execution protection violation - win32 running on AMD64 only
-  // Handled first to avoid misdiagnosis as a "normal" access violation;
-  // This is safe to do because we have a new/unique ExceptionInformation
-  // code for this condition.
-  if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
-    int exception_subcode = (int) exception_record->ExceptionInformation[0];
-    address addr = (address) exception_record->ExceptionInformation[1];
-
-    if (exception_subcode == EXCEPTION_INFO_EXEC_VIOLATION) {
-      size_t page_size = os::vm_page_size();
-
-      // Make sure the pc and the faulting address are sane.
-      //
-      // If an instruction spans a page boundary, and the page containing
-      // the beginning of the instruction is executable but the following
-      // page is not, the pc and the faulting address might be slightly
-      // different - we still want to unguard the 2nd page in this case.
-      //
-      // 15 bytes seems to be a (very) safe value for max instruction size.
-      bool pc_is_near_addr =
-        (pointer_delta((void*) addr, (void*) pc, sizeof(char)) < 15);
-      bool instr_spans_page_boundary =
-        (align_down((intptr_t) pc ^ (intptr_t) addr,
-                         (intptr_t) page_size) > 0);
-
-      if (pc == addr || (pc_is_near_addr && instr_spans_page_boundary)) {
-        static volatile address last_addr =
-          (address) os::non_memory_address_word();
-
-        // In conservative mode, don't unguard unless the address is in the VM
-        if (UnguardOnExecutionViolation > 0 && addr != last_addr &&
-            (UnguardOnExecutionViolation > 1 || os::address_is_in_vm(addr))) {
-
-          // Set memory to RWX and retry
-          address page_start = align_down(addr, page_size);
-          bool res = os::protect_memory((char*) page_start, page_size,
-                                        os::MEM_PROT_RWX);
-
-          log_debug(os)("Execution protection violation "
-                        "at " INTPTR_FORMAT
-                        ", unguarding " INTPTR_FORMAT ": %s", p2i(addr),
-                        p2i(page_start), (res ? "success" : os::strerror(errno)));
-
-          // Set last_addr so if we fault again at the same address, we don't
-          // end up in an endless loop.
-          //
-          // There are two potential complications here.  Two threads trapping
-          // at the same address at the same time could cause one of the
-          // threads to think it already unguarded, and abort the VM.  Likely
-          // very rare.
-          //
-          // The other race involves two threads alternately trapping at
-          // different addresses and failing to unguard the page, resulting in
-          // an endless loop.  This condition is probably even more unlikely
-          // than the first.
-          //
-          // Although both cases could be avoided by using locks or thread
-          // local last_addr, these solutions are unnecessary complication:
-          // this handler is a best-effort safety net, not a complete solution.
-          // It is disabled by default and should only be used as a workaround
-          // in case we missed any no-execute-unsafe VM code.
-
-          last_addr = addr;
-
-          return EXCEPTION_CONTINUE_EXECUTION;
-        }
-      }
-
-      // Last unguard failed or not unguarding
-      tty->print_raw_cr("Execution protection violation");
-#if !defined(USE_VECTORED_EXCEPTION_HANDLING)
-      report_error(t, exception_code, addr, exception_record,
-                   exceptionInfo->ContextRecord);
-#endif
-      return EXCEPTION_CONTINUE_SEARCH;
-    }
-  }
-#endif // _WIN64
-
-#if defined(_M_AMD64) || defined(_M_IX86)
+#if defined(_M_AMD64)
   if ((exception_code == EXCEPTION_ACCESS_VIOLATION) &&
       VM_Version::is_cpuinfo_segv_addr(pc)) {
     // Verify that OS save/restore AVX registers.
     return Handle_Exception(exceptionInfo, VM_Version::cpuinfo_cont_addr());
   }
 
-#if !defined(PRODUCT) && defined(_LP64)
+#if !defined(PRODUCT)
   if ((exception_code == EXCEPTION_ACCESS_VIOLATION) &&
       VM_Version::is_cpuinfo_segv_addr_apx(pc)) {
     // Verify that OS save/restore APX registers.
@@ -2842,7 +2683,6 @@ LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
             return Handle_Exception(exceptionInfo, stub);
           }
         }
-#ifdef _WIN64
         // If it's a legal stack address map the entire region in
         if (thread->is_in_usable_stack(addr)) {
           addr = (address)((uintptr_t)addr &
@@ -2851,7 +2691,6 @@ LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
                             !ExecMem);
           return EXCEPTION_CONTINUE_EXECUTION;
         }
-#endif
         // Null pointer exception.
         if (MacroAssembler::uses_implicit_null_check((void*)addr)) {
           address stub = SharedRuntime::continuation_for_implicit_exception(thread, pc, SharedRuntime::IMPLICIT_NULL);
@@ -2862,7 +2701,6 @@ LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
         return EXCEPTION_CONTINUE_SEARCH;
       }
 
-#ifdef _WIN64
       // Special care for fast JNI field accessors.
       // jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks
       // in and the heap gets shrunk before the field access.
@@ -2870,7 +2708,6 @@ LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
       if (slowcase_pc != (address)-1) {
         return Handle_Exception(exceptionInfo, slowcase_pc);
       }
-#endif
 
       // Stack overflow or null pointer exception in native code.
 #if !defined(USE_VECTORED_EXCEPTION_HANDLING)
@@ -2923,7 +2760,7 @@ LONG WINAPI topLevelExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
       } // switch
     }
 
-#if defined(_M_AMD64) || defined(_M_IX86)
+#if defined(_M_AMD64)
     if ((in_java || in_native) && handle_FLT_exception(exceptionInfo)) {
       return EXCEPTION_CONTINUE_EXECUTION;
     }
@@ -2967,7 +2804,7 @@ LONG WINAPI topLevelVectoredExceptionFilter(struct _EXCEPTION_POINTERS* exceptio
 #elif defined(_M_AMD64)
   address pc = (address) exceptionInfo->ContextRecord->Rip;
 #else
-  address pc = (address) exceptionInfo->ContextRecord->Eip;
+  #error unknown architecture
 #endif
 
   // Fast path for code part of the code cache
@@ -3009,63 +2846,6 @@ LONG WINAPI topLevelUnhandledExceptionFilter(struct _EXCEPTION_POINTERS* excepti
 }
 #endif
 
-#ifndef _WIN64
-// Special care for fast JNI accessors.
-// jni_fast_Get<Primitive>Field can trap at certain pc's if a GC kicks in and
-// the heap gets shrunk before the field access.
-// Need to install our own structured exception handler since native code may
-// install its own.
-LONG WINAPI fastJNIAccessorExceptionFilter(struct _EXCEPTION_POINTERS* exceptionInfo) {
-  DWORD exception_code = exceptionInfo->ExceptionRecord->ExceptionCode;
-  if (exception_code == EXCEPTION_ACCESS_VIOLATION) {
-    address pc = (address) exceptionInfo->ContextRecord->Eip;
-    address addr = JNI_FastGetField::find_slowcase_pc(pc);
-    if (addr != (address)-1) {
-      return Handle_Exception(exceptionInfo, addr);
-    }
-  }
-  return EXCEPTION_CONTINUE_SEARCH;
-}
-
-#define DEFINE_FAST_GETFIELD(Return, Fieldname, Result)                     \
-  Return JNICALL jni_fast_Get##Result##Field_wrapper(JNIEnv *env,           \
-                                                     jobject obj,           \
-                                                     jfieldID fieldID) {    \
-    __try {                                                                 \
-      return (*JNI_FastGetField::jni_fast_Get##Result##Field_fp)(env,       \
-                                                                 obj,       \
-                                                                 fieldID);  \
-    } __except(fastJNIAccessorExceptionFilter((_EXCEPTION_POINTERS*)        \
-                                              _exception_info())) {         \
-    }                                                                       \
-    return 0;                                                               \
-  }
-
-DEFINE_FAST_GETFIELD(jboolean, bool,   Boolean)
-DEFINE_FAST_GETFIELD(jbyte,    byte,   Byte)
-DEFINE_FAST_GETFIELD(jchar,    char,   Char)
-DEFINE_FAST_GETFIELD(jshort,   short,  Short)
-DEFINE_FAST_GETFIELD(jint,     int,    Int)
-DEFINE_FAST_GETFIELD(jlong,    long,   Long)
-DEFINE_FAST_GETFIELD(jfloat,   float,  Float)
-DEFINE_FAST_GETFIELD(jdouble,  double, Double)
-
-address os::win32::fast_jni_accessor_wrapper(BasicType type) {
-  switch (type) {
-  case T_BOOLEAN: return (address)jni_fast_GetBooleanField_wrapper;
-  case T_BYTE:    return (address)jni_fast_GetByteField_wrapper;
-  case T_CHAR:    return (address)jni_fast_GetCharField_wrapper;
-  case T_SHORT:   return (address)jni_fast_GetShortField_wrapper;
-  case T_INT:     return (address)jni_fast_GetIntField_wrapper;
-  case T_LONG:    return (address)jni_fast_GetLongField_wrapper;
-  case T_FLOAT:   return (address)jni_fast_GetFloatField_wrapper;
-  case T_DOUBLE:  return (address)jni_fast_GetDoubleField_wrapper;
-  default:        ShouldNotReachHere();
-  }
-  return (address)-1;
-}
-#endif
-
 // Virtual Memory
 
 // Windows large page support is available on Windows 2003. In order to use
@@ -3341,12 +3121,7 @@ size_t os::win32::large_page_init_decide_size() {
     return 0;
   }
 
-#if defined(IA32)
-  if (size > 4 * M || LargePageSizeInBytes > 4 * M) {
-    WARN("JVM cannot use large pages bigger than 4mb.");
-    return 0;
-  }
-#elif defined(AMD64)
+#if defined(AMD64)
   if (!EnableAllLargePageSizesForWindows) {
     if (size > 4 * M || LargePageSizeInBytes > 4 * M) {
       WARN("JVM cannot use large pages bigger than 4mb.");
@@ -3430,13 +3205,8 @@ char* os::map_memory_to_file(char* base, size_t size, int fd) {
   assert(fd != -1, "File descriptor is not valid");
 
   HANDLE fh = (HANDLE)_get_osfhandle(fd);
-#ifdef _LP64
   HANDLE fileMapping = CreateFileMapping(fh, nullptr, PAGE_READWRITE,
     (DWORD)(size >> 32), (DWORD)(size & 0xFFFFFFFF), nullptr);
-#else
-  HANDLE fileMapping = CreateFileMapping(fh, nullptr, PAGE_READWRITE,
-    0, (DWORD)size, nullptr);
-#endif
   if (fileMapping == nullptr) {
     if (GetLastError() == ERROR_DISK_FULL) {
       vm_exit_during_initialization(err_msg("Could not allocate sufficient disk space for Java heap"));
@@ -4618,32 +4388,6 @@ bool os::message_box(const char* title, const char* message) {
   return result == IDYES;
 }
 
-#ifndef PRODUCT
-#ifndef _WIN64
-// Helpers to check whether NX protection is enabled
-int nx_exception_filter(_EXCEPTION_POINTERS *pex) {
-  if (pex->ExceptionRecord->ExceptionCode == EXCEPTION_ACCESS_VIOLATION &&
-      pex->ExceptionRecord->NumberParameters > 0 &&
-      pex->ExceptionRecord->ExceptionInformation[0] ==
-      EXCEPTION_INFO_EXEC_VIOLATION) {
-    return EXCEPTION_EXECUTE_HANDLER;
-  }
-  return EXCEPTION_CONTINUE_SEARCH;
-}
-
-void nx_check_protection() {
-  // If NX is enabled we'll get an exception calling into code on the stack
-  char code[] = { (char)0xC3 }; // ret
-  void *code_ptr = (void *)code;
-  __try {
-    __asm call code_ptr
-  } __except(nx_exception_filter((_EXCEPTION_POINTERS*)_exception_info())) {
-    tty->print_raw_cr("NX protection detected.");
-  }
-}
-#endif // _WIN64
-#endif // PRODUCT
-
 // This is called _before_ the global arguments have been parsed
 void os::init(void) {
   _initial_pid = _getpid();
@@ -4663,9 +4407,6 @@ void os::init(void) {
     fatal("DuplicateHandle failed\n");
   }
   main_thread_id = (int) GetCurrentThreadId();
-
-  // initialize fast thread access - only used for 32-bit
-  win32::initialize_thread_ptr_offset();
 }
 
 // To install functions for atexit processing
@@ -4681,11 +4422,7 @@ static jint initSock();
 // HotSpot guard pages is added later.
 size_t os::_compiler_thread_min_stack_allowed = 48 * K;
 size_t os::_java_thread_min_stack_allowed = 40 * K;
-#ifdef _LP64
 size_t os::_vm_internal_thread_min_stack_allowed = 64 * K;
-#else
-size_t os::_vm_internal_thread_min_stack_allowed = (48 DEBUG_ONLY(+ 4)) * K;
-#endif // _LP64
 
 // If stack_commit_size is 0, windows will reserve the default size,
 // but only commit a small portion of it.  This stack size is the size of this
@@ -4713,16 +4450,6 @@ jint os::init_2(void) {
   previousUnhandledExceptionFilter = SetUnhandledExceptionFilter(topLevelUnhandledExceptionFilter);
 #endif
 
-  // for debugging float code generation bugs
-#if defined(ASSERT) && !defined(_WIN64)
-  static long fp_control_word = 0;
-  __asm { fstcw fp_control_word }
-  // see Intel PPro Manual, Vol. 2, p 7-16
-  const long invalid   = 0x01;
-  fp_control_word |= invalid;
-  __asm { fldcw fp_control_word }
-#endif
-
   // Check and sets minimum stack sizes against command line options
   if (set_minimum_stack_sizes() == JNI_ERR) {
     return JNI_ERR;
@@ -4746,11 +4473,6 @@ jint os::init_2(void) {
     }
   }
 
-#ifndef _WIN64
-  // Print something if NX is enabled (win32 on AMD64)
-  NOT_PRODUCT(if (PrintMiscellaneous && Verbose) nx_check_protection());
-#endif
-
   // initialize thread priority policy
   prio_init();
 
@@ -6006,13 +5728,6 @@ ssize_t os::raw_send(int fd, char* buf, size_t nBytes, uint flags) {
   return ::send(fd, buf, (int)nBytes, flags);
 }
 
-// WINDOWS CONTEXT Flags for THREAD_SAMPLING
-#if defined(IA32)
-  #define sampling_context_flags (CONTEXT_FULL | CONTEXT_FLOATING_POINT | CONTEXT_EXTENDED_REGISTERS)
-#elif defined(AMD64) || defined(_M_ARM64)
-  #define sampling_context_flags (CONTEXT_FULL | CONTEXT_FLOATING_POINT)
-#endif
-
 // returns true if thread could be suspended,
 // false otherwise
 static bool do_suspend(HANDLE* h) {
@@ -6057,7 +5772,7 @@ void SuspendedThreadTask::internal_do_task() {
 
   // suspend the thread
   if (do_suspend(&h)) {
-    ctxt.ContextFlags = sampling_context_flags;
+    ctxt.ContextFlags = (CONTEXT_FULL | CONTEXT_FLOATING_POINT);
     // get thread context
     GetThreadContext(h, &ctxt);
     SuspendedThreadTaskContext context(_thread, &ctxt);
@@ -6103,7 +5818,6 @@ void* os::get_default_process_handle() {
 
 // Builds a platform dependent Agent_OnLoad_<lib_name> function name
 // which is used to find statically linked in agents.
-// Additionally for windows, takes into account __stdcall names.
 // Parameters:
 //            sym_name: Symbol in library we are looking for
 //            lib_name: Name of library to look in, null for shared libs.
@@ -6144,24 +5858,11 @@ char* os::build_agent_function_name(const char *sym_name, const char *lib_name,
   if (agent_entry_name == nullptr) {
     return nullptr;
   }
+
+  strcpy(agent_entry_name, sym_name);
   if (lib_name != nullptr) {
-    const char *p = strrchr(sym_name, '@');
-    if (p != nullptr && p != sym_name) {
-      // sym_name == _Agent_OnLoad@XX
-      strncpy(agent_entry_name, sym_name, (p - sym_name));
-      agent_entry_name[(p-sym_name)] = '\0';
-      // agent_entry_name == _Agent_OnLoad
-      strcat(agent_entry_name, "_");
-      strncat(agent_entry_name, lib_name, name_len);
-      strcat(agent_entry_name, p);
-      // agent_entry_name == _Agent_OnLoad_lib_name@XX
-    } else {
-      strcpy(agent_entry_name, sym_name);
-      strcat(agent_entry_name, "_");
-      strncat(agent_entry_name, lib_name, name_len);
-    }
-  } else {
-    strcpy(agent_entry_name, sym_name);
+    strcat(agent_entry_name, "_");
+    strncat(agent_entry_name, lib_name, name_len);
   }
   return agent_entry_name;
 }
@@ -6200,19 +5901,6 @@ int os::get_signal_number(const char* name) {
   return -1;
 }
 
-// Fast current thread access
-
-int os::win32::_thread_ptr_offset = 0;
-
-static void call_wrapper_dummy() {}
-
-// We need to call the os_exception_wrapper once so that it sets
-// up the offset from FS of the thread pointer.
-void os::win32::initialize_thread_ptr_offset() {
-  os::os_exception_wrapper((java_call_t)call_wrapper_dummy,
-                           nullptr, methodHandle(), nullptr, nullptr);
-}
-
 bool os::supports_map_sync() {
   return false;
 }
@@ -6287,7 +5975,7 @@ bool os::win32::find_mapping(address addr, mapping_info_t* mi) {
 // Helper for print_one_mapping: print n words, both as hex and ascii.
 // Use Safefetch for all values.
 static void print_snippet(const void* p, outputStream* st) {
-  static const int num_words = LP64_ONLY(3) NOT_LP64(6);
+  static const int num_words = 3;
   static const int num_bytes = num_words * sizeof(int);
   intptr_t v[num_words];
   const int errval = 0xDE210244;
@@ -6330,8 +6018,7 @@ static address print_one_mapping(MEMORY_BASIC_INFORMATION* minfo, address start,
     if (first_line) {
       st->print("Base " PTR_FORMAT ": ", p2i(allocation_base));
     } else {
-      st->print_raw(NOT_LP64 ("                 ")
-                    LP64_ONLY("                         "));
+      st->print_raw("                         ");
     }
     address region_start = (address)minfo->BaseAddress;
     address region_end = region_start + minfo->RegionSize;
@@ -6431,7 +6118,7 @@ void os::print_memory_mappings(char* addr, size_t bytes, outputStream* st) {
       // Here, we advance the probe pointer by alloc granularity. But if the range to print
       //  is large, this may take a long time. Therefore lets stop right away if the address
       //  is outside of what we know are valid addresses on Windows. Also, add a loop fuse.
-      static const address end_virt = (address)(LP64_ONLY(0x7ffffffffffULL) NOT_LP64(3*G));
+      static const address end_virt = (address)(0x7ffffffffffULL);
       if (p >= end_virt) {
         break;
       } else {
diff --git a/src/hotspot/os/windows/os_windows.hpp b/src/hotspot/os/windows/os_windows.hpp
index 1d523724300..1aba43fb3d2 100644
--- a/src/hotspot/os/windows/os_windows.hpp
+++ b/src/hotspot/os/windows/os_windows.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -146,22 +146,7 @@ class os::win32 {
   // return information about that area.
   static bool find_mapping(address p, mapping_info_t* mapping_info);
 
-#ifndef _WIN64
-  // A wrapper to install a structured exception handler for fast JNI accessors.
-  static address fast_jni_accessor_wrapper(BasicType);
-#endif
-
-  // Fast access to current thread
-protected:
-  static int _thread_ptr_offset;
-private:
-  static void initialize_thread_ptr_offset();
 public:
-  static inline void set_thread_ptr_offset(int offset) {
-    _thread_ptr_offset = offset;
-  }
-  static inline int get_thread_ptr_offset() { return _thread_ptr_offset; }
-
   // signal support
   static void* install_signal_handler(int sig, signal_handler_t handler);
   static void* user_handler();
diff --git a/src/hotspot/os/windows/sharedRuntimeRem.cpp b/src/hotspot/os/windows/sharedRuntimeRem.cpp
index cb47cb7dfff..62a85e55a01 100644
--- a/src/hotspot/os/windows/sharedRuntimeRem.cpp
+++ b/src/hotspot/os/windows/sharedRuntimeRem.cpp
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2015, 2023, Oracle and/or its affiliates. All rights reserved.
+* Copyright (c) 2015, 2024, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
@@ -25,7 +25,6 @@
 #include "precompiled.hpp"
 #include "runtime/sharedRuntime.hpp"
 
-#ifdef _WIN64
 // These are copied defines originally from fdlibm.h.
 
 #define __HI(x) *(1+(int*)&x)
@@ -158,5 +157,3 @@ double SharedRuntime::fmod_winx64(double x, double y)
   }
   return x;               /* exact output */
 }
-
-#endif
diff --git a/src/hotspot/os_cpu/windows_x86/assembler_windows_x86.cpp b/src/hotspot/os_cpu/windows_x86/assembler_windows_x86.cpp
index aa1d5820637..c541213615c 100644
--- a/src/hotspot/os_cpu/windows_x86/assembler_windows_x86.cpp
+++ b/src/hotspot/os_cpu/windows_x86/assembler_windows_x86.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -24,41 +24,7 @@
 
 #include "precompiled.hpp"
 #include "asm/macroAssembler.hpp"
-#include "asm/macroAssembler.inline.hpp"
-#include "os_windows.hpp"
-#include "runtime/os.hpp"
 
 void MacroAssembler::int3() {
   emit_int8((unsigned char)0xCC);
 }
-
-#ifndef _LP64
-//  The current scheme to accelerate access to the thread
-//  pointer is to store the current thread in the os_exception_wrapper
-//  and reference the current thread from stubs and compiled code
-//  via the FS register.  FS[0] contains a pointer to the structured
-//  exception block which is actually a stack address.  The first time
-//  we call the os exception wrapper, we calculate and store the
-//  offset from this exception block and use that offset here.
-//
-//  The last mechanism we used was problematic in that the
-//  the offset we had hard coded in the VM kept changing as Microsoft
-//  evolved the OS.
-//
-// Warning: This mechanism assumes that we only attempt to get the
-//          thread when we are nested below a call wrapper.
-//
-// movl reg, fs:[0]                        Get exception pointer
-// movl reg, [reg + thread_ptr_offset]     Load thread
-//
-void MacroAssembler::get_thread(Register thread) {
-  prefix(FS_segment);
-  movptr(thread, ExternalAddress(nullptr));
-  assert(os::win32::get_thread_ptr_offset() != 0,
-         "Thread Pointer Offset has not been initialized");
-  movl(thread, Address(thread, os::win32::get_thread_ptr_offset()));
-}
-
-// #else - use shared x86 implementation in cpu/x86/vm/macroAssembler_x86.cpp
-
-#endif
diff --git a/src/hotspot/os_cpu/windows_x86/atomic_windows_x86.hpp b/src/hotspot/os_cpu/windows_x86/atomic_windows_x86.hpp
index aa0fef3b83a..9f7da19b328 100644
--- a/src/hotspot/os_cpu/windows_x86/atomic_windows_x86.hpp
+++ b/src/hotspot/os_cpu/windows_x86/atomic_windows_x86.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -111,79 +111,4 @@ DEFINE_INTRINSIC_CMPXCHG(InterlockedCompareExchange64, __int64)
 
 #undef DEFINE_INTRINSIC_CMPXCHG
 
-#ifndef AMD64
-
-#pragma warning(disable: 4035) // Disables warnings reporting missing return statement
-
-template<>
-template<typename T>
-inline T Atomic::PlatformLoad<8>::operator()(T const volatile* src) const {
-  STATIC_ASSERT(8 == sizeof(T));
-  volatile T dest;
-  volatile T* pdest = &dest;
-  __asm {
-    mov eax, src
-    fild     qword ptr [eax]
-    mov eax, pdest
-    fistp    qword ptr [eax]
-  }
-  return dest;
-}
-
-template<>
-template<typename T>
-inline void Atomic::PlatformStore<8>::operator()(T volatile* dest,
-                                                 T store_value) const {
-  STATIC_ASSERT(8 == sizeof(T));
-  volatile T* src = &store_value;
-  __asm {
-    mov eax, src
-    fild     qword ptr [eax]
-    mov eax, dest
-    fistp    qword ptr [eax]
-  }
-}
-
-#pragma warning(default: 4035) // Enables warnings reporting missing return statement
-
-template<>
-struct Atomic::PlatformOrderedStore<1, RELEASE_X_FENCE>
-{
-  template <typename T>
-  void operator()(volatile T* p, T v) const {
-    __asm {
-      mov edx, p;
-      mov al, v;
-      xchg al, byte ptr [edx];
-    }
-  }
-};
-
-template<>
-struct Atomic::PlatformOrderedStore<2, RELEASE_X_FENCE>
-{
-  template <typename T>
-  void operator()(volatile T* p, T v) const {
-    __asm {
-      mov edx, p;
-      mov ax, v;
-      xchg ax, word ptr [edx];
-    }
-  }
-};
-
-template<>
-struct Atomic::PlatformOrderedStore<4, RELEASE_X_FENCE>
-{
-  template <typename T>
-  void operator()(volatile T* p, T v) const {
-    __asm {
-      mov edx, p;
-      mov eax, v;
-      xchg eax, dword ptr [edx];
-    }
-  }
-};
-#endif // AMD64
-
 #endif // OS_CPU_WINDOWS_X86_ATOMIC_WINDOWS_X86_HPP
diff --git a/src/hotspot/os_cpu/windows_x86/copy_windows_x86.hpp b/src/hotspot/os_cpu/windows_x86/copy_windows_x86.hpp
index 6f4678e4a5c..4298542629b 100644
--- a/src/hotspot/os_cpu/windows_x86/copy_windows_x86.hpp
+++ b/src/hotspot/os_cpu/windows_x86/copy_windows_x86.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -53,35 +53,7 @@ static void pd_conjoint_jints_atomic(const jint* from, jint* to, size_t count) {
 }
 
 static void pd_conjoint_jlongs_atomic(const jlong* from, jlong* to, size_t count) {
-#ifdef AMD64
   pd_conjoint_atomic_helper(from, to, count);
-#else
-  // Guarantee use of fild/fistp or xmm regs via some asm code, because compilers won't.
-  __asm {
-    mov    eax, from;
-    mov    edx, to;
-    mov    ecx, count;
-    cmp    eax, edx;
-    jbe    downtest;
-    jmp    uptest;
-  up:
-    fild   qword ptr [eax];
-    fistp  qword ptr [edx];
-    add    eax, 8;
-    add    edx, 8;
-  uptest:
-    sub    ecx, 1;
-    jge    up;
-    jmp    done;
-  down:
-    fild   qword ptr [eax][ecx*8];
-    fistp  qword ptr [edx][ecx*8];
-  downtest:
-    sub    ecx, 1;
-    jge    down;
-  done:;
-  }
-#endif // AMD64
 }
 
 static void pd_conjoint_oops_atomic(const oop* from, oop* to, size_t count) {
@@ -89,11 +61,7 @@ static void pd_conjoint_oops_atomic(const oop* from, oop* to, size_t count) {
 }
 
 static void pd_arrayof_conjoint_bytes(const HeapWord* from, HeapWord* to, size_t count) {
-#ifdef AMD64
   pd_conjoint_bytes_atomic(from, to, count);
-#else
-  pd_conjoint_bytes(from, to, count);
-#endif // AMD64
 }
 
 static void pd_arrayof_conjoint_jshorts(const HeapWord* from, HeapWord* to, size_t count) {
diff --git a/src/hotspot/os_cpu/windows_x86/orderAccess_windows_x86.hpp b/src/hotspot/os_cpu/windows_x86/orderAccess_windows_x86.hpp
index 43764b14a01..a1f1aa76912 100644
--- a/src/hotspot/os_cpu/windows_x86/orderAccess_windows_x86.hpp
+++ b/src/hotspot/os_cpu/windows_x86/orderAccess_windows_x86.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -48,13 +48,7 @@ inline void OrderAccess::acquire()    { compiler_barrier(); }
 inline void OrderAccess::release()    { compiler_barrier(); }
 
 inline void OrderAccess::fence() {
-#ifdef AMD64
   StubRoutines_fence();
-#else
-  __asm {
-    lock add dword ptr [esp], 0;
-  }
-#endif // AMD64
   compiler_barrier();
 }
 
diff --git a/src/hotspot/os_cpu/windows_x86/os_windows_x86.cpp b/src/hotspot/os_cpu/windows_x86/os_windows_x86.cpp
index f67e5df8e3e..9a23ac67335 100644
--- a/src/hotspot/os_cpu/windows_x86/os_windows_x86.cpp
+++ b/src/hotspot/os_cpu/windows_x86/os_windows_x86.cpp
@@ -56,15 +56,9 @@
 #undef REG_SP
 #undef REG_FP
 #undef REG_PC
-#ifdef AMD64
 #define REG_SP Rsp
 #define REG_FP Rbp
 #define REG_PC Rip
-#else
-#define REG_SP Esp
-#define REG_FP Ebp
-#define REG_PC Eip
-#endif // AMD64
 
 JNIEXPORT
 extern LONG WINAPI topLevelExceptionFilter(_EXCEPTION_POINTERS* );
@@ -72,52 +66,12 @@ extern LONG WINAPI topLevelExceptionFilter(_EXCEPTION_POINTERS* );
 // Install a win32 structured exception handler around thread.
 void os::os_exception_wrapper(java_call_t f, JavaValue* value, const methodHandle& method, JavaCallArguments* args, JavaThread* thread) {
   __try {
-
-#ifndef AMD64
-    // We store the current thread in this wrapperthread location
-    // and determine how far away this address is from the structured
-    // exception pointer that FS:[0] points to.  This get_thread
-    // code can then get the thread pointer via FS.
-    //
-    // Warning:  This routine must NEVER be inlined since we'd end up with
-    //           multiple offsets.
-    //
-    volatile Thread* wrapperthread = thread;
-
-    if (os::win32::get_thread_ptr_offset() == 0) {
-      int thread_ptr_offset;
-      __asm {
-        lea eax, dword ptr wrapperthread;
-        sub eax, dword ptr FS:[0H];
-        mov thread_ptr_offset, eax
-      };
-      os::win32::set_thread_ptr_offset(thread_ptr_offset);
-    }
-#ifdef ASSERT
-    // Verify that the offset hasn't changed since we initially captured
-    // it. This might happen if we accidentally ended up with an
-    // inlined version of this routine.
-    else {
-      int test_thread_ptr_offset;
-      __asm {
-        lea eax, dword ptr wrapperthread;
-        sub eax, dword ptr FS:[0H];
-        mov test_thread_ptr_offset, eax
-      };
-      assert(test_thread_ptr_offset == os::win32::get_thread_ptr_offset(),
-             "thread pointer offset from SEH changed");
-    }
-#endif // ASSERT
-#endif // !AMD64
-
     f(value, method, args, thread);
   } __except(topLevelExceptionFilter((_EXCEPTION_POINTERS*)_exception_info())) {
       // Nothing to do.
   }
 }
 
-#ifdef AMD64
-
 // This is the language specific handler for exceptions
 // originating from dynamically generated code.
 // We call the standard structured exception handler
@@ -157,7 +111,6 @@ typedef struct {
   UNWIND_INFO_EH_ONLY unw;
 } DynamicCodeData, *pDynamicCodeData;
 
-#endif // AMD64
 //
 // Register our CodeCache area with the OS so it will dispatch exceptions
 // to our topLevelExceptionFilter when we take an exception in our
@@ -167,8 +120,6 @@ typedef struct {
 // codeCache area
 //
 bool os::win32::register_code_area(char *low, char *high) {
-#ifdef AMD64
-
   ResourceMark rm;
 
   pDynamicCodeData pDCD;
@@ -206,7 +157,6 @@ bool os::win32::register_code_area(char *low, char *high) {
   guarantee(RtlAddFunctionTable(prt, 1, (ULONGLONG)low),
             "Failed to register Dynamic Code Exception Handler with RtlAddFunctionTable");
 
-#endif // AMD64
   return true;
 }
 
@@ -334,20 +284,6 @@ frame os::fetch_frame_from_context(const void* ucVoid) {
   return frame(sp, fp, epc);
 }
 
-#ifndef AMD64
-// Ignore "C4172: returning address of local variable or temporary" on 32bit
-PRAGMA_DIAG_PUSH
-PRAGMA_DISABLE_MSVC_WARNING(4172)
-// Returns an estimate of the current stack pointer. Result must be guaranteed
-// to point into the calling threads stack, and be no lower than the current
-// stack pointer.
-address os::current_stack_pointer() {
-  int dummy;
-  address sp = (address)&dummy;
-  return sp;
-}
-PRAGMA_DIAG_POP
-#else
 // Returns the current stack pointer. Accurate value needed for
 // os::verify_stack_alignment().
 address os::current_stack_pointer() {
@@ -356,7 +292,6 @@ address os::current_stack_pointer() {
                                      StubRoutines::x86::get_previous_sp_entry());
   return (*func)();
 }
-#endif
 
 bool os::win32::get_frame_at_stack_banging_point(JavaThread* thread,
         struct _EXCEPTION_POINTERS* exceptionInfo, address pc, frame* fr) {
@@ -414,7 +349,6 @@ void os::print_context(outputStream *st, const void *context) {
   const CONTEXT* uc = (const CONTEXT*)context;
 
   st->print_cr("Registers:");
-#ifdef AMD64
   st->print(  "RAX=" INTPTR_FORMAT, uc->Rax);
   st->print(", RBX=" INTPTR_FORMAT, uc->Rbx);
   st->print(", RCX=" INTPTR_FORMAT, uc->Rcx);
@@ -446,26 +380,12 @@ void os::print_context(outputStream *st, const void *context) {
                  i, xmm[1], xmm[0]);
   }
   st->print("  MXCSR=" UINT32_FORMAT_X_0, uc->MxCsr);
-#else
-  st->print(  "EAX=" INTPTR_FORMAT, uc->Eax);
-  st->print(", EBX=" INTPTR_FORMAT, uc->Ebx);
-  st->print(", ECX=" INTPTR_FORMAT, uc->Ecx);
-  st->print(", EDX=" INTPTR_FORMAT, uc->Edx);
-  st->cr();
-  st->print(  "ESP=" INTPTR_FORMAT, uc->Esp);
-  st->print(", EBP=" INTPTR_FORMAT, uc->Ebp);
-  st->print(", ESI=" INTPTR_FORMAT, uc->Esi);
-  st->print(", EDI=" INTPTR_FORMAT, uc->Edi);
-  st->cr();
-  st->print(  "EIP=" INTPTR_FORMAT, uc->Eip);
-  st->print(", EFLAGS=" INTPTR_FORMAT, uc->EFlags);
-#endif // AMD64
   st->cr();
   st->cr();
 }
 
 void os::print_register_info(outputStream *st, const void *context, int& continuation) {
-  const int register_count = AMD64_ONLY(16) NOT_AMD64(8);
+  const int register_count = 16;
   int n = continuation;
   assert(n >= 0 && n <= register_count, "Invalid continuation value");
   if (context == nullptr || n == register_count) {
@@ -478,7 +398,6 @@ void os::print_register_info(outputStream *st, const void *context, int& continu
     continuation = n + 1;
 # define CASE_PRINT_REG(n, str, id) case n: st->print(str); print_location(st, uc->id);
     switch (n) {
-#ifdef AMD64
     CASE_PRINT_REG( 0, "RAX=", Rax); break;
     CASE_PRINT_REG( 1, "RBX=", Rbx); break;
     CASE_PRINT_REG( 2, "RCX=", Rcx); break;
@@ -495,16 +414,6 @@ void os::print_register_info(outputStream *st, const void *context, int& continu
     CASE_PRINT_REG(13, "R13=", R13); break;
     CASE_PRINT_REG(14, "R14=", R14); break;
     CASE_PRINT_REG(15, "R15=", R15); break;
-#else
-    CASE_PRINT_REG(0, "EAX=", Eax); break;
-    CASE_PRINT_REG(1, "EBX=", Ebx); break;
-    CASE_PRINT_REG(2, "ECX=", Ecx); break;
-    CASE_PRINT_REG(3, "EDX=", Edx); break;
-    CASE_PRINT_REG(4, "ESP=", Esp); break;
-    CASE_PRINT_REG(5, "EBP=", Ebp); break;
-    CASE_PRINT_REG(6, "ESI=", Esi); break;
-    CASE_PRINT_REG(7, "EDI=", Edi); break;
-#endif // AMD64
     }
 # undef CASE_PRINT_REG
     ++n;
@@ -512,17 +421,7 @@ void os::print_register_info(outputStream *st, const void *context, int& continu
 }
 
 extern "C" int SpinPause () {
-#ifdef AMD64
    return 0 ;
-#else
-   // pause == rep:nop
-   // On systems that don't support pause a rep:nop
-   // is executed as a nop.  The rep: prefix is ignored.
-   _asm {
-      pause ;
-   };
-   return 1 ;
-#endif // AMD64
 }
 
 juint os::cpu_microcode_revision() {
@@ -544,21 +443,15 @@ juint os::cpu_microcode_revision() {
 }
 
 void os::setup_fpu() {
-#ifndef AMD64
-  int fpu_cntrl_word = StubRoutines::x86::fpu_cntrl_wrd_std();
-  __asm fldcw fpu_cntrl_word;
-#endif // !AMD64
 }
 
 #ifndef PRODUCT
 void os::verify_stack_alignment() {
-#ifdef AMD64
   // The current_stack_pointer() calls generated get_previous_sp stub routine.
   // Only enable the assert after the routine becomes available.
   if (StubRoutines::initial_stubs_code() != nullptr) {
     assert(((intptr_t)os::current_stack_pointer() & (StackAlignmentInBytes-1)) == 0, "incorrect stack alignment");
   }
-#endif
 }
 #endif
 
diff --git a/src/hotspot/os_cpu/windows_x86/os_windows_x86.inline.hpp b/src/hotspot/os_cpu/windows_x86/os_windows_x86.inline.hpp
index f7622611da7..0cc457609cc 100644
--- a/src/hotspot/os_cpu/windows_x86/os_windows_x86.inline.hpp
+++ b/src/hotspot/os_cpu/windows_x86/os_windows_x86.inline.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -28,13 +28,11 @@
 #include "runtime/os.hpp"
 #include "os_windows.hpp"
 
-#ifdef AMD64
 #define HAVE_PLATFORM_PRINT_NATIVE_STACK 1
 inline bool os::platform_print_native_stack(outputStream* st, const void* context,
                                      char *buf, int buf_size, address& lastpc) {
   return os::win32::platform_print_native_stack(st, context, buf, buf_size, lastpc);
 }
-#endif
 
 inline jlong os::rdtsc() {
   // 32 bit: 64 bit result in edx:eax
diff --git a/src/hotspot/os_cpu/windows_x86/unwind_windows_x86.hpp b/src/hotspot/os_cpu/windows_x86/unwind_windows_x86.hpp
index 1f66e839fab..ca402a13675 100644
--- a/src/hotspot/os_cpu/windows_x86/unwind_windows_x86.hpp
+++ b/src/hotspot/os_cpu/windows_x86/unwind_windows_x86.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2004, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2004, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,8 +25,6 @@
 #ifndef OS_CPU_WINDOWS_X86_UNWIND_WINDOWS_X86_HPP
 #define OS_CPU_WINDOWS_X86_UNWIND_WINDOWS_X86_HPP
 
-
-#ifdef AMD64
 typedef unsigned char UBYTE;
 
 // This structure is used to define an UNWIND_INFO that
@@ -54,6 +52,4 @@ typedef struct _RUNTIME_FUNCTION {
 } RUNTIME_FUNCTION, *PRUNTIME_FUNCTION;
 */
 
-#endif // AMD64
-
 #endif // OS_CPU_WINDOWS_X86_UNWIND_WINDOWS_X86_HPP
diff --git a/src/hotspot/share/adlc/adlc.hpp b/src/hotspot/share/adlc/adlc.hpp
index 8812066bafa..3e82fe0e210 100644
--- a/src/hotspot/share/adlc/adlc.hpp
+++ b/src/hotspot/share/adlc/adlc.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -50,7 +50,7 @@ using namespace std;
 #ifdef _WIN64
 typedef __int64 intptr_t;
 #else
-typedef int intptr_t;
+#error "Unsupported platform"
 #endif
 #define _INTPTR_T_DEFINED
 #endif
@@ -59,7 +59,7 @@ typedef int intptr_t;
 #ifdef _WIN64
 typedef unsigned __int64 uintptr_t;
 #else
-typedef unsigned int uintptr_t;
+#error "Unsupported platform"
 #endif
 #define _UINTPTR_T_DEFINED
 #endif
diff --git a/src/hotspot/share/adlc/main.cpp b/src/hotspot/share/adlc/main.cpp
index fd270b09443..f15b6e8813f 100644
--- a/src/hotspot/share/adlc/main.cpp
+++ b/src/hotspot/share/adlc/main.cpp
@@ -491,8 +491,6 @@ int get_legal_text(FileBuff &fbuf, char **legal_text)
   return (int) (legal_end - legal_start);
 }
 
-#if !defined(_WIN32) || defined(_WIN64)
 void *operator new( size_t size, int, const char *, int ) throw() {
   return ::operator new( size );
 }
-#endif
diff --git a/src/hotspot/share/classfile/javaClasses.cpp b/src/hotspot/share/classfile/javaClasses.cpp
index c18f23badd1..0dd183e06d4 100644
--- a/src/hotspot/share/classfile/javaClasses.cpp
+++ b/src/hotspot/share/classfile/javaClasses.cpp
@@ -412,12 +412,6 @@ Handle java_lang_String::create_from_platform_dependent_str(const char* str, TRA
   if (_to_java_string_fn == nullptr) {
     void *lib_handle = os::native_java_library();
     _to_java_string_fn = CAST_TO_FN_PTR(to_java_string_fn_t, os::dll_lookup(lib_handle, "JNU_NewStringPlatform"));
-#if defined(_WIN32) && !defined(_WIN64)
-    if (_to_java_string_fn == nullptr) {
-      // On 32 bit Windows, also try __stdcall decorated name
-      _to_java_string_fn = CAST_TO_FN_PTR(to_java_string_fn_t, os::dll_lookup(lib_handle, "_JNU_NewStringPlatform@8"));
-    }
-#endif
     if (_to_java_string_fn == nullptr) {
       fatal("JNU_NewStringPlatform missing");
     }
diff --git a/src/hotspot/share/compiler/compilerDefinitions.cpp b/src/hotspot/share/compiler/compilerDefinitions.cpp
index 7b091d8ade5..ad3d14012ff 100644
--- a/src/hotspot/share/compiler/compilerDefinitions.cpp
+++ b/src/hotspot/share/compiler/compilerDefinitions.cpp
@@ -560,11 +560,6 @@ void CompilerConfig::ergo_initialize() {
 
   if (has_c1()) {
     if (!is_compilation_mode_selected()) {
-#if defined(_WINDOWS) && !defined(_LP64)
-      if (FLAG_IS_DEFAULT(NeverActAsServerClassMachine)) {
-        FLAG_SET_ERGO(NeverActAsServerClassMachine, true);
-      }
-#endif
       if (NeverActAsServerClassMachine) {
         set_client_emulation_mode_flags();
       }
@@ -628,4 +623,3 @@ void CompilerConfig::ergo_initialize() {
   }
 #endif // COMPILER2
 }
-
diff --git a/src/hotspot/share/include/jvm.h b/src/hotspot/share/include/jvm.h
index 28e8c2b08d3..e50d758335c 100644
--- a/src/hotspot/share/include/jvm.h
+++ b/src/hotspot/share/include/jvm.h
@@ -1153,6 +1153,13 @@ JVM_GetClassFileVersion(JNIEnv *env, jclass current);
 JNIEXPORT jboolean JNICALL
 JVM_PrintWarningAtDynamicAgentLoad(void);
 
+#define JNI_ONLOAD_SYMBOLS   {"JNI_OnLoad"}
+#define JNI_ONUNLOAD_SYMBOLS {"JNI_OnUnload"}
+#define JVM_ONLOAD_SYMBOLS      {"JVM_OnLoad"}
+#define AGENT_ONLOAD_SYMBOLS    {"Agent_OnLoad"}
+#define AGENT_ONUNLOAD_SYMBOLS  {"Agent_OnUnload"}
+#define AGENT_ONATTACH_SYMBOLS  {"Agent_OnAttach"}
+
 /*
  * This structure is used by the launcher to get the default thread
  * stack size from the VM using JNI_GetDefaultJavaVMInitArgs() with a
diff --git a/src/hotspot/share/jvmci/jvmciCompilerToVM.cpp b/src/hotspot/share/jvmci/jvmciCompilerToVM.cpp
index b85d2227fc7..3599df18544 100644
--- a/src/hotspot/share/jvmci/jvmciCompilerToVM.cpp
+++ b/src/hotspot/share/jvmci/jvmciCompilerToVM.cpp
@@ -2578,9 +2578,7 @@ C2V_VMENTRY_NULL(jlongArray, registerNativeMethods, (JNIEnv* env, jobject, jclas
       stringStream st;
       char* pure_name = NativeLookup::pure_jni_name(method);
       guarantee(pure_name != nullptr, "Illegal native method name encountered");
-      os::print_jni_name_prefix_on(&st, args_size);
       st.print_raw(pure_name);
-      os::print_jni_name_suffix_on(&st, args_size);
       char* jni_name = st.as_string();
 
       address entry = (address) os::dll_lookup(sl_handle, jni_name);
@@ -2589,10 +2587,8 @@ C2V_VMENTRY_NULL(jlongArray, registerNativeMethods, (JNIEnv* env, jobject, jclas
         st.reset();
         char* long_name = NativeLookup::long_jni_name(method);
         guarantee(long_name != nullptr, "Illegal native method name encountered");
-        os::print_jni_name_prefix_on(&st, args_size);
         st.print_raw(pure_name);
         st.print_raw(long_name);
-        os::print_jni_name_suffix_on(&st, args_size);
         char* jni_long_name = st.as_string();
         entry = (address) os::dll_lookup(sl_handle, jni_long_name);
         if (entry == nullptr) {
diff --git a/src/hotspot/share/prims/jniFastGetField.hpp b/src/hotspot/share/prims/jniFastGetField.hpp
index 525ff0aba87..0e4c4c849e0 100644
--- a/src/hotspot/share/prims/jniFastGetField.hpp
+++ b/src/hotspot/share/prims/jniFastGetField.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2004, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2004, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -71,17 +71,6 @@ class JNI_FastGetField : AllStatic {
 #endif // AARCH64
 
  public:
-#if defined(_WINDOWS) && !defined(_WIN64)
-  static GetBooleanField_t jni_fast_GetBooleanField_fp;
-  static GetByteField_t    jni_fast_GetByteField_fp;
-  static GetCharField_t    jni_fast_GetCharField_fp;
-  static GetShortField_t   jni_fast_GetShortField_fp;
-  static GetIntField_t     jni_fast_GetIntField_fp;
-  static GetLongField_t    jni_fast_GetLongField_fp;
-  static GetFloatField_t   jni_fast_GetFloatField_fp;
-  static GetDoubleField_t  jni_fast_GetDoubleField_fp;
-#endif
-
   static address generate_fast_get_boolean_field();
   static address generate_fast_get_byte_field();
   static address generate_fast_get_char_field();
diff --git a/src/hotspot/share/prims/jvm.cpp b/src/hotspot/share/prims/jvm.cpp
index 9a132b089f2..a027351ff7b 100644
--- a/src/hotspot/share/prims/jvm.cpp
+++ b/src/hotspot/share/prims/jvm.cpp
@@ -378,7 +378,7 @@ JVM_ENTRY(jobjectArray, JVM_GetProperties(JNIEnv *env))
   // Add the sun.management.compiler property for the compiler's name
   {
 #undef CSIZE
-#if defined(_LP64) || defined(_WIN64)
+#if defined(_LP64)
   #define CSIZE "64-Bit "
 #else
   #define CSIZE
diff --git a/src/hotspot/share/prims/jvmtiAgent.cpp b/src/hotspot/share/prims/jvmtiAgent.cpp
index 1231fd5019f..6dd205082a0 100644
--- a/src/hotspot/share/prims/jvmtiAgent.cpp
+++ b/src/hotspot/share/prims/jvmtiAgent.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2023, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -27,6 +27,7 @@
 #include "cds/cds_globals.hpp"
 #include "cds/cdsConfig.hpp"
 #include "jni.h"
+#include "jvm.h"
 #include "jvm_io.h"
 #include "jvmtifiles/jvmtiEnv.hpp"
 #include "prims/jvmtiEnvBase.hpp"
diff --git a/src/hotspot/share/prims/nativeLookup.cpp b/src/hotspot/share/prims/nativeLookup.cpp
index 368d5eb264e..7de782c807b 100644
--- a/src/hotspot/share/prims/nativeLookup.cpp
+++ b/src/hotspot/share/prims/nativeLookup.cpp
@@ -250,9 +250,9 @@ static address lookup_special_native(const char* jni_name) {
   return nullptr;
 }
 
-address NativeLookup::lookup_style(const methodHandle& method, char* pure_name, const char* long_name, int args_size, bool os_style, TRAPS) {
+address NativeLookup::lookup_style(const methodHandle& method, char* pure_name, const char* long_name, int args_size, TRAPS) {
   address entry;
-  const char* jni_name = compute_complete_jni_name(pure_name, long_name, args_size, os_style);
+  const char* jni_name = compute_complete_jni_name(pure_name, long_name, args_size);
 
 
   // If the loader is null we have a system class, so we attempt a lookup in
@@ -306,17 +306,10 @@ address NativeLookup::lookup_style(const methodHandle& method, char* pure_name,
   return entry;
 }
 
-const char* NativeLookup::compute_complete_jni_name(const char* pure_name, const char* long_name, int args_size, bool os_style) {
+const char* NativeLookup::compute_complete_jni_name(const char* pure_name, const char* long_name, int args_size) {
   stringStream st;
-  if (os_style) {
-    os::print_jni_name_prefix_on(&st, args_size);
-  }
-
   st.print_raw(pure_name);
   st.print_raw(long_name);
-  if (os_style) {
-    os::print_jni_name_suffix_on(&st, args_size);
-  }
 
   return st.as_string();
 }
@@ -339,7 +332,7 @@ address NativeLookup::lookup_entry(const methodHandle& method, TRAPS) {
                 + method->size_of_parameters(); // actual parameters
 
   // 1) Try JNI short style
-  entry = lookup_style(method, pure_name, "",        args_size, true,  CHECK_NULL);
+  entry = lookup_style(method, pure_name, "",        args_size, CHECK_NULL);
   if (entry != nullptr) return entry;
 
   // Compute long name
@@ -351,15 +344,7 @@ address NativeLookup::lookup_entry(const methodHandle& method, TRAPS) {
   }
 
   // 2) Try JNI long style
-  entry = lookup_style(method, pure_name, long_name, args_size, true,  CHECK_NULL);
-  if (entry != nullptr) return entry;
-
-  // 3) Try JNI short style without os prefix/suffix
-  entry = lookup_style(method, pure_name, "",        args_size, false, CHECK_NULL);
-  if (entry != nullptr) return entry;
-
-  // 4) Try JNI long style without os prefix/suffix
-  entry = lookup_style(method, pure_name, long_name, args_size, false, CHECK_NULL);
+  entry = lookup_style(method, pure_name, long_name, args_size, CHECK_NULL);
 
   return entry; // null indicates not found
 }
diff --git a/src/hotspot/share/prims/nativeLookup.hpp b/src/hotspot/share/prims/nativeLookup.hpp
index a24768024f7..b9615377e30 100644
--- a/src/hotspot/share/prims/nativeLookup.hpp
+++ b/src/hotspot/share/prims/nativeLookup.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -34,12 +34,12 @@
 class NativeLookup : AllStatic {
  private:
   // Style specific lookup
-  static address lookup_style(const methodHandle& method, char* pure_name, const char* long_name, int args_size, bool os_style, TRAPS);
+  static address lookup_style(const methodHandle& method, char* pure_name, const char* long_name, int args_size, TRAPS);
   static address lookup_base (const methodHandle& method, TRAPS);
   static address lookup_entry(const methodHandle& method, TRAPS);
   static address lookup_entry_prefixed(const methodHandle& method, TRAPS);
 
-  static const char* compute_complete_jni_name(const char* pure_name, const char* long_name, int args_size, bool os_style);
+  static const char* compute_complete_jni_name(const char* pure_name, const char* long_name, int args_size);
  public:
   // JNI name computation
   static char* pure_jni_name(const methodHandle& method);
diff --git a/src/hotspot/share/runtime/os.hpp b/src/hotspot/share/runtime/os.hpp
index 323b8d2df8d..2f665df5bba 100644
--- a/src/hotspot/share/runtime/os.hpp
+++ b/src/hotspot/share/runtime/os.hpp
@@ -882,10 +882,6 @@ class os: AllStatic {
   // Fills in path to jvm.dll/libjvm.so (used by the Disassembler)
   static void     jvm_path(char *buf, jint buflen);
 
-  // JNI names
-  static void     print_jni_name_prefix_on(outputStream* st, int args_size);
-  static void     print_jni_name_suffix_on(outputStream* st, int args_size);
-
   // Init os specific system properties values
   static void init_system_properties_values();
 
diff --git a/src/hotspot/share/runtime/sharedRuntimeTrans.cpp b/src/hotspot/share/runtime/sharedRuntimeTrans.cpp
index 5285819ee96..78788d487b7 100644
--- a/src/hotspot/share/runtime/sharedRuntimeTrans.cpp
+++ b/src/hotspot/share/runtime/sharedRuntimeTrans.cpp
@@ -42,7 +42,7 @@
 // Enabling optimizations in this file causes incorrect code to be
 // generated; can not figure out how to turn down optimization for one
 // file in the IDE on Windows
-#ifdef WIN32
+#ifdef _WINDOWS
 # pragma warning( disable: 4748 ) // /GS can not protect parameters and local variables from local buffer overrun because optimizations are disabled in function
 # pragma optimize ( "", off )
 #endif
@@ -671,6 +671,6 @@ JRT_LEAF(jdouble, SharedRuntime::dpow(jdouble x, jdouble y))
   return __ieee754_pow(x, y);
 JRT_END
 
-#ifdef WIN32
+#ifdef _WINDOWS
 # pragma optimize ( "", on )
 #endif
diff --git a/src/hotspot/share/utilities/globalDefinitions_visCPP.hpp b/src/hotspot/share/utilities/globalDefinitions_visCPP.hpp
index 3b28328d7dd..237d12baa6d 100644
--- a/src/hotspot/share/utilities/globalDefinitions_visCPP.hpp
+++ b/src/hotspot/share/utilities/globalDefinitions_visCPP.hpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -48,6 +48,11 @@
 #define _USE_MATH_DEFINES
 # include <math.h>
 
+// Only 64-bit Windows is supported
+#ifndef _LP64
+#error unsupported platform
+#endif
+
 // 4810578: varargs unsafe on 32-bit integer/64-bit pointer architectures
 // When __cplusplus is defined, NULL is defined as 0 (32-bit constant) in
 // system header files.  On 32-bit architectures, there is no problem.
@@ -61,17 +66,11 @@
 // pointer when it extracts the argument, then we may have a problem.
 //
 // Solution: For 64-bit architectures, redefine NULL as 64-bit constant 0.
-#ifdef _LP64
 #undef NULL
 // 64-bit Windows uses a P64 data model (not LP64, although we define _LP64)
 // Since longs are 32-bit we cannot use 0L here.  Use the Visual C++ specific
 // 64-bit integer-suffix (LL) instead.
 #define NULL 0LL
-#else
-#ifndef NULL
-#define NULL 0
-#endif
-#endif
 
 // NULL vs NULL_WORD:
 // On Linux NULL is defined as a special type '__null'. Assigning __null to
@@ -79,11 +78,7 @@
 // pointer is stored as integer value.
 #define NULL_WORD NULL
 
-#ifdef _WIN64
 typedef int64_t ssize_t;
-#else
-typedef int32_t ssize_t;
-#endif
 
 // Non-standard stdlib-like stuff:
 inline int strcasecmp(const char *s1, const char *s2) { return _stricmp(s1,s2); }
@@ -120,13 +115,8 @@ inline int g_isfinite(jdouble f)                 { return _finite(f); }
 #endif
 
 #ifndef SSIZE_MAX
-#ifdef _LP64
 #define SSIZE_MIN LLONG_MIN
 #define SSIZE_MAX LLONG_MAX
-#else
-#define SSIZE_MIN INT_MIN
-#define SSIZE_MAX INT_MAX
-#endif
 #endif // SSIZE_MAX missing
 
 #endif // SHARE_UTILITIES_GLOBALDEFINITIONS_VISCPP_HPP
diff --git a/src/java.base/share/native/include/jni.h b/src/java.base/share/native/include/jni.h
index 6bbc71ded1f..1a31c38b3ce 100644
--- a/src/java.base/share/native/include/jni.h
+++ b/src/java.base/share/native/include/jni.h
@@ -48,6 +48,8 @@
 extern "C" {
 #endif
 
+#define JNICALL
+
 /*
  * JNI Types
  */
diff --git a/src/java.base/share/native/libjava/NativeLibraries.c b/src/java.base/share/native/libjava/NativeLibraries.c
index 22986306017..df5ff343d61 100644
--- a/src/java.base/share/native/libjava/NativeLibraries.c
+++ b/src/java.base/share/native/libjava/NativeLibraries.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -58,7 +58,6 @@ static jboolean initIDs(JNIEnv *env)
     return JNI_TRUE;
 }
 
-
 /*
  * Support for finding JNI_On(Un)Load_<lib_name> if it exists.
  * If cname == NULL then just find normal JNI_On(Un)Load entry point
@@ -93,7 +92,11 @@ static void *findJniFunction(JNIEnv *env, void *handle,
             JNU_ThrowOutOfMemoryError(env, NULL);
             goto done;
         }
-        buildJniFunctionName(syms[i], cname, jniFunctionName);
+        strcpy(jniFunctionName, syms[i]);
+        if (cname != NULL) {
+            strcat(jniFunctionName, "_");
+            strcat(jniFunctionName, cname);
+        }
         entryName = JVM_FindLibraryEntry(handle, jniFunctionName);
         free(jniFunctionName);
         if(entryName) {
diff --git a/src/java.base/share/native/libjava/jni_util.h b/src/java.base/share/native/libjava/jni_util.h
index 3c73e90d62c..89414697328 100644
--- a/src/java.base/share/native/libjava/jni_util.h
+++ b/src/java.base/share/native/libjava/jni_util.h
@@ -356,9 +356,6 @@ JNIEXPORT void InitializeEncoding(JNIEnv *env, const char *name);
 
 void* getProcessHandle();
 
-void buildJniFunctionName(const char *sym, const char *cname,
-                          char *jniEntryName);
-
 jstring getLastErrorString(JNIEnv *env);
 
 JNIEXPORT int JNICALL
diff --git a/src/java.base/unix/native/include/jni_md.h b/src/java.base/unix/native/include/jni_md.h
index 6e583da7147..b4ed87e0c48 100644
--- a/src/java.base/unix/native/include/jni_md.h
+++ b/src/java.base/unix/native/include/jni_md.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -52,8 +52,6 @@
   #define JNIIMPORT
 #endif
 
-#define JNICALL
-
 typedef int jint;
 #ifdef _LP64
 typedef long jlong;
diff --git a/src/java.base/unix/native/libjava/jni_util_md.c b/src/java.base/unix/native/libjava/jni_util_md.c
index 32b477aa7ac..7195b3defdf 100644
--- a/src/java.base/unix/native/libjava/jni_util_md.c
+++ b/src/java.base/unix/native/libjava/jni_util_md.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -51,15 +51,6 @@ void* getProcessHandle() {
     return procHandle;
 }
 
-void buildJniFunctionName(const char *sym, const char *cname,
-                          char *jniEntryName) {
-    strcpy(jniEntryName, sym);
-    if (cname != NULL) {
-        strcat(jniEntryName, "_");
-        strcat(jniEntryName, cname);
-    }
-}
-
 jstring
 getLastErrorString(JNIEnv *env)
 {
diff --git a/src/java.base/windows/native/include/jni_md.h b/src/java.base/windows/native/include/jni_md.h
index f795421937e..6d217733d82 100644
--- a/src/java.base/windows/native/include/jni_md.h
+++ b/src/java.base/windows/native/include/jni_md.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -30,7 +30,6 @@
   #define JNIEXPORT __declspec(dllexport)
 #endif
 #define JNIIMPORT __declspec(dllimport)
-#define JNICALL __stdcall
 
 typedef int jint;
 typedef long long jlong;
diff --git a/src/java.base/windows/native/libjava/gdefs_md.h b/src/java.base/windows/native/libjava/gdefs_md.h
index 24cc95ff0e7..d7c0e6552a3 100644
--- a/src/java.base/windows/native/libjava/gdefs_md.h
+++ b/src/java.base/windows/native/libjava/gdefs_md.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2003, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -28,8 +28,3 @@
  */
 
 #include <stddef.h>
-#ifndef _WIN64
-typedef int intptr_t;
-typedef unsigned int uintptr_t;
-typedef unsigned long DWORD_PTR, *PDWORD_PTR;
-#endif
diff --git a/src/java.base/windows/native/libjava/java_props_md.c b/src/java.base/windows/native/libjava/java_props_md.c
index d26d6df1aff..03d0acdae1e 100644
--- a/src/java.base/windows/native/libjava/java_props_md.c
+++ b/src/java.base/windows/native/libjava/java_props_md.c
@@ -552,8 +552,6 @@ GetJavaProperties(JNIEnv* env)
         sprops.os_version = _strdup(buf);
 #if defined(_M_AMD64)
         sprops.os_arch = "amd64";
-#elif defined(_X86_)
-        sprops.os_arch = "x86";
 #elif defined(_M_ARM64)
         sprops.os_arch = "aarch64";
 #else
diff --git a/src/java.base/windows/native/libjava/jlong_md.h b/src/java.base/windows/native/libjava/jlong_md.h
index 0e3da8f4947..a5db712b0b0 100644
--- a/src/java.base/windows/native/libjava/jlong_md.h
+++ b/src/java.base/windows/native/libjava/jlong_md.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2002, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -63,15 +63,8 @@
 /* For static variables initialized to zero */
 #define jlong_zero_init ((jlong) 0)
 
-#ifdef _WIN64
 #define jlong_to_ptr(a) ((void*)(a))
 #define ptr_to_jlong(a) ((jlong)(a))
-#else
-/* Double casting to avoid warning messages looking for casting of */
-/* smaller sizes into pointers */
-#define jlong_to_ptr(a) ((void*)(int)(a))
-#define ptr_to_jlong(a) ((jlong)(int)(a))
-#endif
 
 #define jint_to_jlong(a)        ((jlong)(a))
 #define jlong_to_jint(a)        ((jint)(a))
diff --git a/src/java.base/windows/native/libjava/jni_util_md.c b/src/java.base/windows/native/libjava/jni_util_md.c
index 9c64a339aad..672f719bc81 100644
--- a/src/java.base/windows/native/libjava/jni_util_md.c
+++ b/src/java.base/windows/native/libjava/jni_util_md.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2004, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2004, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -35,34 +35,6 @@ void* getProcessHandle() {
     return (void*)GetModuleHandle(NULL);
 }
 
-/*
- * Windows symbols can be simple like JNI_OnLoad or __stdcall format
- * like _JNI_OnLoad@8. We need to handle both.
- */
-void buildJniFunctionName(const char *sym, const char *cname,
-                          char *jniEntryName) {
-    if (cname != NULL) {
-        char *p = strrchr(sym, '@');
-        if (p != NULL && p != sym) {
-            // sym == _JNI_OnLoad@8
-            strncpy(jniEntryName, sym, (p - sym));
-            jniEntryName[(p-sym)] = '\0';
-            // jniEntryName == _JNI_OnLoad
-            strcat(jniEntryName, "_");
-            strcat(jniEntryName, cname);
-            strcat(jniEntryName, p);
-            //jniEntryName == _JNI_OnLoad_cname@8
-        } else {
-            strcpy(jniEntryName, sym);
-            strcat(jniEntryName, "_");
-            strcat(jniEntryName, cname);
-        }
-    } else {
-        strcpy(jniEntryName, sym);
-    }
-    return;
-}
-
 jstring
 getLastErrorString(JNIEnv *env) {
 
diff --git a/src/java.base/windows/native/libjli/java_md.c b/src/java.base/windows/native/libjli/java_md.c
index a1012bcc4f9..c4d38a02831 100644
--- a/src/java.base/windows/native/libjli/java_md.c
+++ b/src/java.base/windows/native/libjli/java_md.c
@@ -681,7 +681,7 @@ void* SplashProcAddress(const char* name) {
 /*
  * Signature adapter for _beginthreadex().
  */
-static unsigned __stdcall ThreadJavaMain(void* args) {
+static unsigned ThreadJavaMain(void* args) {
     return (unsigned)JavaMain(args);
 }
 
diff --git a/src/java.base/windows/native/libnio/ch/WindowsSelectorImpl.c b/src/java.base/windows/native/libnio/ch/WindowsSelectorImpl.c
index 96a3f5ad5c1..deea97dcceb 100644
--- a/src/java.base/windows/native/libnio/ch/WindowsSelectorImpl.c
+++ b/src/java.base/windows/native/libnio/ch/WindowsSelectorImpl.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -69,9 +69,7 @@ Java_sun_nio_ch_WindowsSelectorImpl_00024SubSelector_poll0(JNIEnv *env, jobject
     static struct timeval zerotime = {0, 0};
     int read_count = 0, write_count = 0, except_count = 0;
 
-#ifdef _WIN64
     int resultbuf[FD_SETSIZE + 1];
-#endif
 
     if (timeout == 0) {
         tv = &zerotime;
@@ -121,7 +119,6 @@ Java_sun_nio_ch_WindowsSelectorImpl_00024SubSelector_poll0(JNIEnv *env, jobject
     /* Return selected sockets. */
     /* Each Java array consists of sockets count followed by sockets list */
 
-#ifdef _WIN64
     resultbuf[0] = readfds->fd_count;
     for (i = 0; i < (int)readfds->fd_count; i++) {
         resultbuf[i + 1] = (int)readfds->fd_array[i];
@@ -142,15 +139,7 @@ Java_sun_nio_ch_WindowsSelectorImpl_00024SubSelector_poll0(JNIEnv *env, jobject
     }
     (*env)->SetIntArrayRegion(env, returnExceptFds, 0,
                               exceptfds->fd_count + 1, resultbuf);
-#else
-    (*env)->SetIntArrayRegion(env, returnReadFds, 0,
-                              readfds->fd_count + 1, (jint *)readfds);
 
-    (*env)->SetIntArrayRegion(env, returnWriteFds, 0,
-                              writefds->fd_count + 1, (jint *)writefds);
-    (*env)->SetIntArrayRegion(env, returnExceptFds, 0,
-                              exceptfds->fd_count + 1, (jint *)exceptfds);
-#endif
     return 0;
 }
 
diff --git a/src/java.base/windows/native/libnio/ch/nio_util.h b/src/java.base/windows/native/libnio/ch/nio_util.h
index b90e0ac63d5..e7bef3d39cb 100644
--- a/src/java.base/windows/native/libnio/ch/nio_util.h
+++ b/src/java.base/windows/native/libnio/ch/nio_util.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -47,26 +47,14 @@ jint convertReturnVal(JNIEnv *env, jint n, jboolean r);
 jlong convertLongReturnVal(JNIEnv *env, jlong n, jboolean r);
 jboolean purgeOutstandingICMP(JNIEnv *env, jclass clazz, jint fd);
 
-#ifdef _WIN64
-
 struct iovec {
     jlong  iov_base;
     jint  iov_len;
 };
 
-#else
-
-struct iovec {
-    jint  iov_base;
-    jint  iov_len;
-};
-
-#endif
-
 /* Defined in UnixDomainSockets.c */
 
 jbyteArray sockaddrToUnixAddressBytes(JNIEnv *env, struct sockaddr_un *sa, socklen_t len);
 
 jint unixSocketAddressToSockaddr(JNIEnv *env, jbyteArray uaddr,
                                 struct sockaddr_un *sa, int *len);
-
diff --git a/src/java.desktop/share/native/libawt/java2d/pipe/ShapeSpanIterator.c b/src/java.desktop/share/native/libawt/java2d/pipe/ShapeSpanIterator.c
index 333231c508f..4f973a7037d 100644
--- a/src/java.desktop/share/native/libawt/java2d/pipe/ShapeSpanIterator.c
+++ b/src/java.desktop/share/native/libawt/java2d/pipe/ShapeSpanIterator.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -849,16 +849,6 @@ PCPathDone(PathConsumerVec *consumer)
     return oom;
 }
 
-/*
- * REMIND: CDECL needed for WIN32 "qsort"
- */
-
-#ifdef _WIN32
-#define CDECL __cdecl
-#else
-#define CDECL
-#endif
-
 #define SUBDIVIDE_MAX   10
 #define MAX_FLAT_SQ     (1.0 * 1.0)
 #define GROW_SIZE       20
@@ -1171,7 +1161,7 @@ subdivideCubic(pathData *pd, int level,
     return appendSegment(pd, x0, y0, x3, y3);
 }
 
-static int CDECL
+static int
 sortSegmentsByLeadingY(const void *elem1, const void *elem2)
 {
     segmentData *seg1 = *(segmentData **)elem1;
diff --git a/src/java.desktop/windows/native/libawt/windows/ThemeReader.cpp b/src/java.desktop/windows/native/libawt/windows/ThemeReader.cpp
index fad778dac4e..ec5a1b4c54e 100644
--- a/src/java.desktop/windows/native/libawt/windows/ThemeReader.cpp
+++ b/src/java.desktop/windows/native/libawt/windows/ThemeReader.cpp
@@ -41,53 +41,53 @@
 #define GREEN_SHIFT 8
 
 
-typedef HRESULT(__stdcall *PFNCLOSETHEMEDATA)(HTHEME hTheme);
+typedef HRESULT(*PFNCLOSETHEMEDATA)(HTHEME hTheme);
 
-typedef HRESULT(__stdcall *PFNDRAWTHEMEBACKGROUND)(HTHEME hTheme, HDC hdc,
+typedef HRESULT(*PFNDRAWTHEMEBACKGROUND)(HTHEME hTheme, HDC hdc,
         int iPartId, int iStateId, const RECT *pRect,  const RECT *pClipRect);
 
-typedef HTHEME(__stdcall *PFNOPENTHEMEDATA)(HWND hwnd, LPCWSTR pszClassList);
-typedef HTHEME(__stdcall *PFNOPENTHEMEDATAFORDPI)(HWND hwnd, LPCWSTR pszClassList, UINT dpi);
+typedef HTHEME(*PFNOPENTHEMEDATA)(HWND hwnd, LPCWSTR pszClassList);
+typedef HTHEME(*PFNOPENTHEMEDATAFORDPI)(HWND hwnd, LPCWSTR pszClassList, UINT dpi);
 
-typedef HRESULT (__stdcall *PFNDRAWTHEMETEXT)(HTHEME hTheme, HDC hdc,
+typedef HRESULT (*PFNDRAWTHEMETEXT)(HTHEME hTheme, HDC hdc,
           int iPartId, int iStateId, LPCWSTR pszText, int iCharCount,
           DWORD dwTextFlags, DWORD dwTextFlags2, const RECT *pRect);
 
-typedef HRESULT (__stdcall *PFNGETTHEMEBACKGROUNDCONTENTRECT)(HTHEME hTheme,
+typedef HRESULT (*PFNGETTHEMEBACKGROUNDCONTENTRECT)(HTHEME hTheme,
         HDC hdc, int iPartId, int iStateId,  const RECT *pBoundingRect,
         RECT *pContentRect);
 
-typedef HRESULT (__stdcall *PFNGETTHEMEMARGINS)(HTHEME hTheme,
+typedef HRESULT (*PFNGETTHEMEMARGINS)(HTHEME hTheme,
         OPTIONAL HDC hdc, int iPartId, int iStateId, int iPropId,
         OPTIONAL RECT *prc, OUT MARGINS *pMargins);
 
-typedef BOOL (__stdcall *PFNISTHEMEPARTDEFINED)(HTHEME hTheme, int iPartId, int iStateId);
+typedef BOOL (*PFNISTHEMEPARTDEFINED)(HTHEME hTheme, int iPartId, int iStateId);
 
-typedef HRESULT (__stdcall *PFNGETTHEMEBOOL)(HTHEME hTheme, int iPartId,
+typedef HRESULT (*PFNGETTHEMEBOOL)(HTHEME hTheme, int iPartId,
         int iStateId, int iPropId, BOOL *pfVal);
 
-typedef BOOL (__stdcall *PFNGETTHEMESYSBOOL)(HTHEME hTheme, int iPropId);
+typedef BOOL (*PFNGETTHEMESYSBOOL)(HTHEME hTheme, int iPropId);
 
-typedef HRESULT (__stdcall *PFNGETTHEMECOLOR)(HTHEME hTheme, int iPartId,
+typedef HRESULT (*PFNGETTHEMECOLOR)(HTHEME hTheme, int iPartId,
         int iStateId, int iPropId, COLORREF *pColor);
 
-typedef HRESULT (__stdcall *PFNGETTHEMEENUMVALUE)(HTHEME hTheme, int iPartId,
+typedef HRESULT (*PFNGETTHEMEENUMVALUE)(HTHEME hTheme, int iPartId,
         int iStateId, int iPropId, int *val);
-typedef HRESULT (__stdcall *PFNGETTHEMEINT)(HTHEME hTheme, int iPartId,
+typedef HRESULT (*PFNGETTHEMEINT)(HTHEME hTheme, int iPartId,
         int iStateId, int iPropId, int *val);
-typedef HRESULT (__stdcall *PFNGETTHEMEPARTSIZE)(HTHEME hTheme, HDC hdc,
+typedef HRESULT (*PFNGETTHEMEPARTSIZE)(HTHEME hTheme, HDC hdc,
         int iPartId, int iStateId, RECT *prc, THEMESIZE eSize, SIZE *size);
 
-typedef HRESULT (__stdcall *PFNGETTHEMEPOSITION)(HTHEME hTheme, int iPartId,
+typedef HRESULT (*PFNGETTHEMEPOSITION)(HTHEME hTheme, int iPartId,
         int iStateId, int propID, POINT *point);
 
-typedef HRESULT(__stdcall *PFNSETWINDOWTHEME)(HWND hwnd, LPCWSTR pszSubAppName,
+typedef HRESULT(*PFNSETWINDOWTHEME)(HWND hwnd, LPCWSTR pszSubAppName,
             LPCWSTR pszSubIdList);
 
-typedef BOOL (__stdcall *PFNISTHEMEBACKGROUNDPARTIALLYTRANSPARENT)
+typedef BOOL (*PFNISTHEMEBACKGROUNDPARTIALLYTRANSPARENT)
              (HTHEME hTheme, int iPartId, int iStateId);
 
-typedef HRESULT (__stdcall *PFNGETTHEMETRANSITIONDURATION)
+typedef HRESULT (*PFNGETTHEMETRANSITIONDURATION)
                 (HTHEME hTheme, int iPartId, int iStateIdFrom, int iStateIdTo,
                  int iPropId, DWORD *pdwDuration);
 
diff --git a/src/java.desktop/windows/native/libawt/windows/alloc.h b/src/java.desktop/windows/native/libawt/windows/alloc.h
index 4c92c12cbca..a5796df40b1 100644
--- a/src/java.desktop/windows/native/libawt/windows/alloc.h
+++ b/src/java.desktop/windows/native/libawt/windows/alloc.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -117,7 +117,7 @@ void handle_bad_alloc(void);
     void *safe_Malloc_outofmem(size_t size, const char *, int);
     void *safe_Calloc_outofmem(size_t num, size_t size, const char *, int);
     void *safe_Realloc_outofmem(void *memblock, size_t size, const char *, int);
-    void * CDECL operator new(size_t size, const char *, int);
+    void * operator new(size_t size, const char *, int);
 
     #define safe_Malloc(size) \
         safe_Malloc_outofmem(size, __FILE__, __LINE__)
diff --git a/src/java.desktop/windows/native/libawt/windows/awt.h b/src/java.desktop/windows/native/libawt/windows/awt.h
index 3703bfbb0cb..b6289dcae68 100644
--- a/src/java.desktop/windows/native/libawt/windows/awt.h
+++ b/src/java.desktop/windows/native/libawt/windows/awt.h
@@ -154,15 +154,6 @@ typedef AwtObject* PDATA;
                                                      JNI_TRUE)
 /*  /NEW JNI */
 
-/*
- * IS_WIN64 returns TRUE on 64-bit Itanium
- */
-#if defined (_WIN64)
-    #define IS_WIN64 TRUE
-#else
-    #define IS_WIN64 FALSE
-#endif
-
 /*
  * IS_WIN2000 returns TRUE on 2000, XP and Vista
  * IS_WINXP returns TRUE on XP and Vista
@@ -195,35 +186,6 @@ extern JavaVM *jvm;
 #define JNU_GetStringPlatformChars(env, x, y) reinterpret_cast<LPCWSTR>(env->GetStringChars(x, y))
 #define JNU_ReleaseStringPlatformChars(env, x, y) env->ReleaseStringChars(x, reinterpret_cast<const jchar*>(y))
 
-/*
- * Itanium symbols needed for 64-bit compilation.
- * These are defined in winuser.h in the August 2001 MSDN update.
- */
-#ifndef GCLP_HBRBACKGROUND
-    #ifdef _WIN64
-        #error Macros for GetClassLongPtr, etc. are for 32-bit windows only
-    #endif /* !_WIN64 */
-    #define GetClassLongPtr GetClassLong
-    #define SetClassLongPtr SetClassLong
-    #define GCLP_HBRBACKGROUND GCL_HBRBACKGROUND
-    #define GCLP_HCURSOR GCL_HCURSOR
-    #define GCLP_HICON GCL_HICON
-    #define GCLP_HICONSM GCL_HICONSM
-    #define GCLP_HMODULE GCL_HMODULE
-    #define GCLP_MENUNAME GCL_MENUNAME
-    #define GCLP_WNDPROC GCL_WNDPROC
-    #define GetWindowLongPtr GetWindowLong
-    #define SetWindowLongPtr SetWindowLong
-    #define GWLP_WNDPROC GWL_WNDPROC
-    #define GWLP_HINSTANCE GWL_HINSTANCE
-    #define GWLP_HWNDPARENT GWL_HWNDPARENT
-    #define GWLP_ID GWL_ID
-    #define GWLP_USERDATA GWL_USERDATA
-    #define DWLP_DLGPROC DWL_DLGPROC
-    #define DWLP_MSGRESULT DWL_MSGRESULT
-    #define DWLP_USER DWL_USER
-#endif /* !GCLP_HBRBACKGROUND */
-
 /*
  * macros for saving and restoring FPU control word
  * NOTE: float.h must be defined if using these macros
diff --git a/src/java.desktop/windows/native/libawt/windows/awt_Debug.cpp b/src/java.desktop/windows/native/libawt/windows/awt_Debug.cpp
index 3b8043385a1..b6e8b2c2e0e 100644
--- a/src/java.desktop/windows/native/libawt/windows/awt_Debug.cpp
+++ b/src/java.desktop/windows/native/libawt/windows/awt_Debug.cpp
@@ -160,11 +160,7 @@ void AwtDebugSupport::AssertCallback(const char * expr, const char * file, int l
 
     // if clicked Yes, break into the debugger
     if ( ret == IDYES ) {
-        # if defined(_M_IX86)
-            _asm { int 3 };
-        # else
-            DebugBreak();
-        # endif
+        DebugBreak();
     }
     // otherwise, try to continue execution
 }
diff --git a/src/java.desktop/windows/native/libawt/windows/awt_DnDDS.cpp b/src/java.desktop/windows/native/libawt/windows/awt_DnDDS.cpp
index 2c67b65cc41..a329f5b84b3 100644
--- a/src/java.desktop/windows/native/libawt/windows/awt_DnDDS.cpp
+++ b/src/java.desktop/windows/native/libawt/windows/awt_DnDDS.cpp
@@ -71,8 +71,8 @@ typedef std::map<FORMATETC, STGMEDIUM> CDataMap;
                           java_awt_event_InputEvent_BUTTON3_DOWN_MASK)
 
 extern "C" {
-DWORD __cdecl convertActionsToDROPEFFECT(jint actions);
-jint  __cdecl convertDROPEFFECTToActions(DWORD effects);
+DWORD convertActionsToDROPEFFECT(jint actions);
+jint  convertDROPEFFECTToActions(DWORD effects);
 }
 
 class PictureDragHelper
@@ -525,8 +525,7 @@ void AwtDragSource::SetCursor(jobject cursor) {
  * MatchFormatEtc
  */
 
-HRESULT __stdcall
-AwtDragSource::MatchFormatEtc(FORMATETC __RPC_FAR *pFormatEtcIn,
+HRESULT AwtDragSource::MatchFormatEtc(FORMATETC __RPC_FAR *pFormatEtcIn,
                               FORMATETC *cacheEnt) {
     TRY;
 
@@ -586,7 +585,7 @@ AwtDragSource::MatchFormatEtc(FORMATETC __RPC_FAR *pFormatEtcIn,
  * QueryInterface
  */
 
-HRESULT __stdcall AwtDragSource::QueryInterface(REFIID riid, void __RPC_FAR *__RPC_FAR *ppvObject) {
+HRESULT AwtDragSource::QueryInterface(REFIID riid, void __RPC_FAR *__RPC_FAR *ppvObject) {
     TRY;
 
     if (riid == IID_IUnknown) {
@@ -613,7 +612,7 @@ HRESULT __stdcall AwtDragSource::QueryInterface(REFIID riid, void __RPC_FAR *__R
  * AddRef
  */
 
-ULONG __stdcall AwtDragSource::AddRef() {
+ULONG AwtDragSource::AddRef() {
     return (ULONG)++m_refs;
 }
 
@@ -621,7 +620,7 @@ ULONG __stdcall AwtDragSource::AddRef() {
  * Release
  */
 
-ULONG __stdcall AwtDragSource::Release() {
+ULONG AwtDragSource::Release() {
     int refs;
 
     if ((refs = --m_refs) == 0) delete this;
@@ -633,7 +632,7 @@ ULONG __stdcall AwtDragSource::Release() {
  * QueryContinueDrag
  */
 
-HRESULT __stdcall  AwtDragSource::QueryContinueDrag(BOOL fEscapeKeyPressed, DWORD grfKeyState) {
+HRESULT AwtDragSource::QueryContinueDrag(BOOL fEscapeKeyPressed, DWORD grfKeyState) {
     AwtToolkit::GetInstance().eventNumber++;
     TRY;
 
@@ -687,7 +686,7 @@ HRESULT __stdcall  AwtDragSource::QueryContinueDrag(BOOL fEscapeKeyPressed, DWOR
  * GiveFeedback
  */
 
-HRESULT __stdcall  AwtDragSource::GiveFeedback(DWORD dwEffect) {
+HRESULT AwtDragSource::GiveFeedback(DWORD dwEffect) {
     AwtToolkit::GetInstance().eventNumber++;
     TRY;
 
@@ -766,7 +765,7 @@ HRESULT __stdcall  AwtDragSource::GiveFeedback(DWORD dwEffect) {
  * GetData
  */
 
-HRESULT __stdcall AwtDragSource::GetData(FORMATETC __RPC_FAR *pFormatEtc,
+HRESULT AwtDragSource::GetData(FORMATETC __RPC_FAR *pFormatEtc,
                                          STGMEDIUM __RPC_FAR *pmedium) {
     AwtToolkit::GetInstance().eventNumber++;
     TRY;
@@ -941,7 +940,7 @@ HRESULT __stdcall AwtDragSource::GetData(FORMATETC __RPC_FAR *pFormatEtc,
  * GetDataHere
  */
 
-HRESULT __stdcall AwtDragSource::GetDataHere(FORMATETC __RPC_FAR *pFormatEtc,
+HRESULT AwtDragSource::GetDataHere(FORMATETC __RPC_FAR *pFormatEtc,
                                              STGMEDIUM __RPC_FAR *pmedium) {
     AwtToolkit::GetInstance().eventNumber++;
     TRY;
@@ -1045,7 +1044,7 @@ HRESULT __stdcall AwtDragSource::GetDataHere(FORMATETC __RPC_FAR *pFormatEtc,
  * QueryGetData
  */
 
-HRESULT __stdcall  AwtDragSource::QueryGetData(FORMATETC __RPC_FAR *pFormatEtc) {
+HRESULT AwtDragSource::QueryGetData(FORMATETC __RPC_FAR *pFormatEtc) {
     AwtToolkit::GetInstance().eventNumber++;
     TRY;
 
@@ -1059,7 +1058,7 @@ HRESULT __stdcall  AwtDragSource::QueryGetData(FORMATETC __RPC_FAR *pFormatEtc)
  * GetCanonicalFormatEtc
  */
 
-HRESULT __stdcall  AwtDragSource::GetCanonicalFormatEtc(FORMATETC __RPC_FAR *pFormatEtcIn, FORMATETC __RPC_FAR *pFormatEtcOut) {
+HRESULT AwtDragSource::GetCanonicalFormatEtc(FORMATETC __RPC_FAR *pFormatEtcIn, FORMATETC __RPC_FAR *pFormatEtcOut) {
     AwtToolkit::GetInstance().eventNumber++;
     TRY;
 
@@ -1080,7 +1079,7 @@ HRESULT __stdcall  AwtDragSource::GetCanonicalFormatEtc(FORMATETC __RPC_FAR *pFo
  * SetData
  */
 
-HRESULT __stdcall AwtDragSource::SetData(FORMATETC __RPC_FAR *pFormatEtc, STGMEDIUM __RPC_FAR *pmedium, BOOL fRelease) {
+HRESULT AwtDragSource::SetData(FORMATETC __RPC_FAR *pFormatEtc, STGMEDIUM __RPC_FAR *pmedium, BOOL fRelease) {
     AwtToolkit::GetInstance().eventNumber++;
     if (pFormatEtc->cfFormat == CF_PERFORMEDDROPEFFECT && pmedium->tymed == TYMED_HGLOBAL) {
         m_dwPerformedDropEffect = *(DWORD*)::GlobalLock(pmedium->hGlobal);
@@ -1103,7 +1102,7 @@ HRESULT __stdcall AwtDragSource::SetData(FORMATETC __RPC_FAR *pFormatEtc, STGMED
  * EnumFormatEtc
  */
 
-HRESULT __stdcall  AwtDragSource::EnumFormatEtc(DWORD dwDirection, IEnumFORMATETC *__RPC_FAR *ppenumFormatEtc) {
+HRESULT AwtDragSource::EnumFormatEtc(DWORD dwDirection, IEnumFORMATETC *__RPC_FAR *ppenumFormatEtc) {
     AwtToolkit::GetInstance().eventNumber++;
     TRY;
 
@@ -1117,7 +1116,7 @@ HRESULT __stdcall  AwtDragSource::EnumFormatEtc(DWORD dwDirection, IEnumFORMATET
  * DAdvise
  */
 
-HRESULT __stdcall  AwtDragSource::DAdvise(FORMATETC __RPC_FAR *pFormatEtc, DWORD advf, IAdviseSink __RPC_FAR *pAdvSink, DWORD __RPC_FAR *pdwConnection) {
+HRESULT AwtDragSource::DAdvise(FORMATETC __RPC_FAR *pFormatEtc, DWORD advf, IAdviseSink __RPC_FAR *pAdvSink, DWORD __RPC_FAR *pdwConnection) {
     AwtToolkit::GetInstance().eventNumber++;
     return E_NOTIMPL;
 }
@@ -1126,7 +1125,7 @@ HRESULT __stdcall  AwtDragSource::DAdvise(FORMATETC __RPC_FAR *pFormatEtc, DWORD
  * DUnadvise
  */
 
-HRESULT __stdcall  AwtDragSource::DUnadvise(DWORD dwConnection) {
+HRESULT AwtDragSource::DUnadvise(DWORD dwConnection) {
     AwtToolkit::GetInstance().eventNumber++;
     return OLE_E_ADVISENOTSUPPORTED;
 }
@@ -1135,7 +1134,7 @@ HRESULT __stdcall  AwtDragSource::DUnadvise(DWORD dwConnection) {
  * EnumAdvise
  */
 
-HRESULT __stdcall  AwtDragSource::EnumDAdvise(IEnumSTATDATA __RPC_FAR *__RPC_FAR *ppenumAdvise) {
+HRESULT AwtDragSource::EnumDAdvise(IEnumSTATDATA __RPC_FAR *__RPC_FAR *ppenumAdvise) {
     AwtToolkit::GetInstance().eventNumber++;
     return OLE_E_ADVISENOTSUPPORTED;
 }
@@ -1143,7 +1142,7 @@ HRESULT __stdcall  AwtDragSource::EnumDAdvise(IEnumSTATDATA __RPC_FAR *__RPC_FAR
 const UINT AwtDragSource::PROCESS_ID_FORMAT =
     ::RegisterClipboardFormat(TEXT("_SUNW_JAVA_AWT_PROCESS_ID"));
 
-HRESULT __stdcall AwtDragSource::GetProcessId(FORMATETC __RPC_FAR *pFormatEtc, STGMEDIUM __RPC_FAR *pmedium) {
+HRESULT AwtDragSource::GetProcessId(FORMATETC __RPC_FAR *pFormatEtc, STGMEDIUM __RPC_FAR *pmedium) {
     AwtToolkit::GetInstance().eventNumber++;
     if ((pFormatEtc->tymed & TYMED_HGLOBAL) == 0) {
         return DV_E_TYMED;
@@ -1294,7 +1293,7 @@ AwtDragSource::ADSIEnumFormatEtc::~ADSIEnumFormatEtc() {
  * QueryInterface
  */
 
-HRESULT __stdcall  AwtDragSource::ADSIEnumFormatEtc::QueryInterface(REFIID riid, void __RPC_FAR *__RPC_FAR *ppvObject) {
+HRESULT AwtDragSource::ADSIEnumFormatEtc::QueryInterface(REFIID riid, void __RPC_FAR *__RPC_FAR *ppvObject) {
     TRY;
 
     if (riid == IID_IUnknown) {
@@ -1317,7 +1316,7 @@ HRESULT __stdcall  AwtDragSource::ADSIEnumFormatEtc::QueryInterface(REFIID riid,
  * AddRef
  */
 
-ULONG __stdcall  AwtDragSource::ADSIEnumFormatEtc::AddRef(void) {
+ULONG AwtDragSource::ADSIEnumFormatEtc::AddRef(void) {
     return (ULONG)++m_refs;
 }
 
@@ -1325,7 +1324,7 @@ ULONG __stdcall  AwtDragSource::ADSIEnumFormatEtc::AddRef(void) {
  * Release
  */
 
-ULONG __stdcall  AwtDragSource::ADSIEnumFormatEtc::Release(void) {
+ULONG AwtDragSource::ADSIEnumFormatEtc::Release(void) {
     int refs;
 
     if ((refs = --m_refs) == 0) delete this;
@@ -1337,7 +1336,7 @@ ULONG __stdcall  AwtDragSource::ADSIEnumFormatEtc::Release(void) {
  * Next
  */
 
-HRESULT _stdcall AwtDragSource::ADSIEnumFormatEtc::Next(ULONG celt, FORMATETC __RPC_FAR *rgelt, ULONG __RPC_FAR *pceltFetched) {
+HRESULT AwtDragSource::ADSIEnumFormatEtc::Next(ULONG celt, FORMATETC __RPC_FAR *rgelt, ULONG __RPC_FAR *pceltFetched) {
     TRY;
 
     unsigned int len = m_parent->getNTypes();
@@ -1359,7 +1358,7 @@ HRESULT _stdcall AwtDragSource::ADSIEnumFormatEtc::Next(ULONG celt, FORMATETC __
  * Skip
  */
 
-HRESULT __stdcall  AwtDragSource::ADSIEnumFormatEtc::Skip(ULONG celt) {
+HRESULT AwtDragSource::ADSIEnumFormatEtc::Skip(ULONG celt) {
     TRY;
 
     unsigned int len = m_parent->getNTypes();
@@ -1382,7 +1381,7 @@ HRESULT __stdcall  AwtDragSource::ADSIEnumFormatEtc::Skip(ULONG celt) {
  * Reset
  */
 
-HRESULT __stdcall  AwtDragSource::ADSIEnumFormatEtc::Reset(void) {
+HRESULT AwtDragSource::ADSIEnumFormatEtc::Reset(void) {
     m_idx = 0;
 
     return S_OK;
@@ -1392,7 +1391,7 @@ HRESULT __stdcall  AwtDragSource::ADSIEnumFormatEtc::Reset(void) {
  * Clone
  */
 
-HRESULT __stdcall  AwtDragSource::ADSIEnumFormatEtc::Clone(IEnumFORMATETC  __RPC_FAR *__RPC_FAR *ppenum) {
+HRESULT AwtDragSource::ADSIEnumFormatEtc::Clone(IEnumFORMATETC  __RPC_FAR *__RPC_FAR *ppenum) {
     TRY;
 
     *ppenum = new ADSIEnumFormatEtc(m_parent);
@@ -1484,7 +1483,7 @@ AwtDragSource::ADSIStreamProxy::~ADSIStreamProxy() {
  * QueryInterface
  */
 
-HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::QueryInterface(REFIID riid, void __RPC_FAR *__RPC_FAR *ppvObject) {
+HRESULT AwtDragSource::ADSIStreamProxy::QueryInterface(REFIID riid, void __RPC_FAR *__RPC_FAR *ppvObject) {
     TRY;
 
     if (riid == IID_IUnknown) {
@@ -1507,7 +1506,7 @@ HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::QueryInterface(REFIID riid, v
  * AddRef
  */
 
-ULONG __stdcall  AwtDragSource::ADSIStreamProxy::AddRef(void) {
+ULONG AwtDragSource::ADSIStreamProxy::AddRef(void) {
     return (ULONG)++m_refs;
 }
 
@@ -1515,7 +1514,7 @@ ULONG __stdcall  AwtDragSource::ADSIStreamProxy::AddRef(void) {
  * Release
  */
 
-ULONG __stdcall  AwtDragSource::ADSIStreamProxy::Release(void) {
+ULONG AwtDragSource::ADSIStreamProxy::Release(void) {
     int refs;
 
     if ((refs = --m_refs) == 0) delete this;
@@ -1527,7 +1526,7 @@ ULONG __stdcall  AwtDragSource::ADSIStreamProxy::Release(void) {
  * Read
  */
 
-HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::Read(void __RPC_FAR *pv, ULONG cb, ULONG __RPC_FAR *pcbRead) {
+HRESULT AwtDragSource::ADSIStreamProxy::Read(void __RPC_FAR *pv, ULONG cb, ULONG __RPC_FAR *pcbRead) {
     TRY;
 
     unsigned int rem  = m_blen - m_off;
@@ -1552,7 +1551,7 @@ HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::Read(void __RPC_FAR *pv, ULON
  * Write
  */
 
-HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::Write(const void __RPC_FAR *pv, ULONG cb, ULONG __RPC_FAR *pcbWritten) {
+HRESULT AwtDragSource::ADSIStreamProxy::Write(const void __RPC_FAR *pv, ULONG cb, ULONG __RPC_FAR *pcbWritten) {
     TRY;
 
     if (pcbWritten != (ULONG __RPC_FAR *)NULL) {
@@ -1570,7 +1569,7 @@ HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::Write(const void __RPC_FAR *p
  * Seek
  */
 
-HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::Seek(LARGE_INTEGER dlibMove, DWORD dwOrigin, ULARGE_INTEGER __RPC_FAR *plibNewPosition) {
+HRESULT AwtDragSource::ADSIStreamProxy::Seek(LARGE_INTEGER dlibMove, DWORD dwOrigin, ULARGE_INTEGER __RPC_FAR *plibNewPosition) {
     TRY;
 
     if (dlibMove.HighPart != 0) return STG_E_INVALIDPOINTER;
@@ -1618,7 +1617,7 @@ HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::Seek(LARGE_INTEGER dlibMove,
  * SetSize
  */
 
-HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::SetSize(ULARGE_INTEGER libNewSize) {
+HRESULT AwtDragSource::ADSIStreamProxy::SetSize(ULARGE_INTEGER libNewSize) {
     return STG_E_INVALIDFUNCTION;
 }
 
@@ -1626,7 +1625,7 @@ HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::SetSize(ULARGE_INTEGER libNew
  * CopyTo
  */
 
-HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::CopyTo(IStream __RPC_FAR *pstm, ULARGE_INTEGER cb, ULARGE_INTEGER __RPC_FAR *pcbRead, ULARGE_INTEGER __RPC_FAR *pcbWritten) {
+HRESULT AwtDragSource::ADSIStreamProxy::CopyTo(IStream __RPC_FAR *pstm, ULARGE_INTEGER cb, ULARGE_INTEGER __RPC_FAR *pcbRead, ULARGE_INTEGER __RPC_FAR *pcbWritten) {
     TRY;
 
     ULONG written = 0;
@@ -1659,7 +1658,7 @@ HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::CopyTo(IStream __RPC_FAR *pst
  * Commit
  */
 
-HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::Commit(DWORD grfCommitFlags) {
+HRESULT AwtDragSource::ADSIStreamProxy::Commit(DWORD grfCommitFlags) {
     return S_OK;
 }
 
@@ -1667,7 +1666,7 @@ HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::Commit(DWORD grfCommitFlags)
  * Revert
  */
 
-HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::Revert() {
+HRESULT AwtDragSource::ADSIStreamProxy::Revert() {
     return S_OK;
 }
 
@@ -1675,7 +1674,7 @@ HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::Revert() {
  * LockRegion
  */
 
-HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::LockRegion(ULARGE_INTEGER libOffset, ULARGE_INTEGER cb, DWORD dwLockType) {
+HRESULT AwtDragSource::ADSIStreamProxy::LockRegion(ULARGE_INTEGER libOffset, ULARGE_INTEGER cb, DWORD dwLockType) {
     return STG_E_INVALIDFUNCTION;
 }
 
@@ -1683,7 +1682,7 @@ HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::LockRegion(ULARGE_INTEGER lib
  * UnlockRegion
  */
 
-HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::UnlockRegion(ULARGE_INTEGER libOffset, ULARGE_INTEGER cb, DWORD dwLockType) {
+HRESULT AwtDragSource::ADSIStreamProxy::UnlockRegion(ULARGE_INTEGER libOffset, ULARGE_INTEGER cb, DWORD dwLockType) {
     return STG_E_INVALIDFUNCTION;
 }
 
@@ -1691,7 +1690,7 @@ HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::UnlockRegion(ULARGE_INTEGER l
  * Stat
  */
 
-HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::Stat(STATSTG __RPC_FAR *pstatstg, DWORD grfStatFlag) {
+HRESULT AwtDragSource::ADSIStreamProxy::Stat(STATSTG __RPC_FAR *pstatstg, DWORD grfStatFlag) {
     TRY;
 
     *pstatstg = m_statstg;
@@ -1707,7 +1706,7 @@ HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::Stat(STATSTG __RPC_FAR *pstat
  * Clone
  */
 
-HRESULT __stdcall  AwtDragSource::ADSIStreamProxy::Clone(IStream __RPC_FAR *__RPC_FAR *ppstm) {
+HRESULT AwtDragSource::ADSIStreamProxy::Clone(IStream __RPC_FAR *__RPC_FAR *ppstm) {
     TRY;
 
     *ppstm = new ADSIStreamProxy(this);
diff --git a/src/java.desktop/windows/native/libawt/windows/awt_DnDDS.h b/src/java.desktop/windows/native/libawt/windows/awt_DnDDS.h
index 6b22b46cd7c..ba41d81da82 100644
--- a/src/java.desktop/windows/native/libawt/windows/awt_DnDDS.h
+++ b/src/java.desktop/windows/native/libawt/windows/awt_DnDDS.h
@@ -53,33 +53,33 @@ class AwtDragSource : virtual public IDropSource, virtual public IDataObject {
 
         // IUnknown
 
-        virtual HRESULT __stdcall QueryInterface(REFIID riid, void __RPC_FAR *__RPC_FAR *ppvObject);
+        virtual HRESULT QueryInterface(REFIID riid, void __RPC_FAR *__RPC_FAR *ppvObject);
 
-        virtual ULONG   __stdcall AddRef(void);
-        virtual ULONG   __stdcall Release(void);
+        virtual ULONG   AddRef(void);
+        virtual ULONG   Release(void);
 
         // IDropSource
 
-        virtual HRESULT __stdcall QueryContinueDrag(BOOL fEscapeKeyPressed, DWORD grfKeyState);
+        virtual HRESULT QueryContinueDrag(BOOL fEscapeKeyPressed, DWORD grfKeyState);
 
-        virtual HRESULT __stdcall GiveFeedback(DWORD dwEffect);
+        virtual HRESULT GiveFeedback(DWORD dwEffect);
 
         // IDataObject
 
-        virtual HRESULT __stdcall GetData(FORMATETC __RPC_FAR *pFormatEtc, STGMEDIUM __RPC_FAR *pmedium);
-        virtual HRESULT __stdcall GetDataHere(FORMATETC __RPC_FAR *pFormatEtc, STGMEDIUM __RPC_FAR *pmedium);
+        virtual HRESULT GetData(FORMATETC __RPC_FAR *pFormatEtc, STGMEDIUM __RPC_FAR *pmedium);
+        virtual HRESULT GetDataHere(FORMATETC __RPC_FAR *pFormatEtc, STGMEDIUM __RPC_FAR *pmedium);
 
-        virtual HRESULT __stdcall QueryGetData(FORMATETC __RPC_FAR *pFormatEtc);
+        virtual HRESULT QueryGetData(FORMATETC __RPC_FAR *pFormatEtc);
 
-        virtual HRESULT __stdcall GetCanonicalFormatEtc(FORMATETC __RPC_FAR *pFormatEtcIn, FORMATETC __RPC_FAR *pFormatEtcOut);
+        virtual HRESULT GetCanonicalFormatEtc(FORMATETC __RPC_FAR *pFormatEtcIn, FORMATETC __RPC_FAR *pFormatEtcOut);
 
-        virtual HRESULT __stdcall SetData(FORMATETC __RPC_FAR *pFormatEtc, STGMEDIUM __RPC_FAR *pmedium, BOOL fRelease);
+        virtual HRESULT SetData(FORMATETC __RPC_FAR *pFormatEtc, STGMEDIUM __RPC_FAR *pmedium, BOOL fRelease);
 
-        virtual HRESULT __stdcall EnumFormatEtc(DWORD dwDirection, IEnumFORMATETC *__RPC_FAR *ppenumFormatEtc);
+        virtual HRESULT EnumFormatEtc(DWORD dwDirection, IEnumFORMATETC *__RPC_FAR *ppenumFormatEtc);
 
-        virtual HRESULT __stdcall DAdvise(FORMATETC __RPC_FAR *pFormatEtc, DWORD advf, IAdviseSink __RPC_FAR *pAdvSink, DWORD __RPC_FAR *pdwConnection);
-        virtual HRESULT __stdcall DUnadvise(DWORD dwConnection);
-        virtual HRESULT __stdcall EnumDAdvise(IEnumSTATDATA __RPC_FAR *__RPC_FAR *ppenumAdvise);
+        virtual HRESULT DAdvise(FORMATETC __RPC_FAR *pFormatEtc, DWORD advf, IAdviseSink __RPC_FAR *pAdvSink, DWORD __RPC_FAR *pdwConnection);
+        virtual HRESULT DUnadvise(DWORD dwConnection);
+        virtual HRESULT EnumDAdvise(IEnumSTATDATA __RPC_FAR *__RPC_FAR *ppenumAdvise);
 
 
         // AwtDragSource
@@ -104,7 +104,7 @@ class AwtDragSource : virtual public IDropSource, virtual public IDataObject {
 
         INLINE void Signal() { ::ReleaseMutex(m_mutex); }
 
-        virtual HRESULT __stdcall GetProcessId(FORMATETC __RPC_FAR *pFormatEtc, STGMEDIUM __RPC_FAR *pmedium);
+        virtual HRESULT GetProcessId(FORMATETC __RPC_FAR *pFormatEtc, STGMEDIUM __RPC_FAR *pmedium);
 
     protected:
         INLINE void WaitUntilSignalled(BOOL retain) {
@@ -117,14 +117,14 @@ class AwtDragSource : virtual public IDropSource, virtual public IDataObject {
 
         static void _DoDragDrop(void* param);
 
-        HRESULT __stdcall MatchFormatEtc(FORMATETC __RPC_FAR *pFormatEtcIn, FORMATETC *cacheEnt);
+        HRESULT MatchFormatEtc(FORMATETC __RPC_FAR *pFormatEtcIn, FORMATETC *cacheEnt);
 
    private:
 
         void LoadCache(jlongArray formats);
         void UnloadCache();
 
-        static int __cdecl _compar(const void *, const void *);
+        static int _compar(const void *, const void *);
 
         static void call_dSCenter(JNIEnv* env, jobject self, jint targetActions,
                                   jint modifiers, POINT pt);
@@ -151,17 +151,17 @@ class AwtDragSource : virtual public IDropSource, virtual public IDataObject {
 
                 // IUnknown
 
-                virtual HRESULT __stdcall QueryInterface(REFIID riid, void __RPC_FAR *__RPC_FAR *ppvObject);
+                virtual HRESULT QueryInterface(REFIID riid, void __RPC_FAR *__RPC_FAR *ppvObject);
 
-                virtual ULONG   __stdcall AddRef(void);
-                virtual ULONG   __stdcall Release(void);
+                virtual ULONG   AddRef(void);
+                virtual ULONG   Release(void);
 
                 // IEnumFORMATETC
 
-                virtual HRESULT _stdcall Next(ULONG celt, FORMATETC __RPC_FAR *rgelt, ULONG __RPC_FAR *pceltFetched);
-                virtual HRESULT _stdcall Skip(ULONG celt);
-                virtual HRESULT _stdcall Reset();
-                virtual HRESULT _stdcall Clone(IEnumFORMATETC __RPC_FAR *__RPC_FAR *ppenum);
+                virtual HRESULT Next(ULONG celt, FORMATETC __RPC_FAR *rgelt, ULONG __RPC_FAR *pceltFetched);
+                virtual HRESULT Skip(ULONG celt);
+                virtual HRESULT Reset();
+                virtual HRESULT Clone(IEnumFORMATETC __RPC_FAR *__RPC_FAR *ppenum);
 
             private:
                 AwtDragSource*  m_parent;
@@ -181,35 +181,35 @@ class AwtDragSource : virtual public IDropSource, virtual public IDataObject {
 
                 // IUnknown
 
-                virtual HRESULT __stdcall QueryInterface(REFIID riid, void __RPC_FAR *__RPC_FAR *ppvObject);
+                virtual HRESULT QueryInterface(REFIID riid, void __RPC_FAR *__RPC_FAR *ppvObject);
 
-                virtual ULONG   __stdcall AddRef(void);
-                virtual ULONG   __stdcall Release(void);
+                virtual ULONG   AddRef(void);
+                virtual ULONG   Release(void);
 
                 // IStream
 
 
-                virtual  HRESULT __stdcall Read(void __RPC_FAR *pv, ULONG cb, ULONG __RPC_FAR *pcbRead);
+                virtual  HRESULT Read(void __RPC_FAR *pv, ULONG cb, ULONG __RPC_FAR *pcbRead);
 
-                virtual  HRESULT __stdcall Write(const void __RPC_FAR *pv, ULONG cb, ULONG __RPC_FAR *pcbWritten);
+                virtual  HRESULT Write(const void __RPC_FAR *pv, ULONG cb, ULONG __RPC_FAR *pcbWritten);
 
-                virtual  HRESULT __stdcall Seek(LARGE_INTEGER dlibMove, DWORD dwOrigin, ULARGE_INTEGER __RPC_FAR *plibNewPosition);
+                virtual  HRESULT Seek(LARGE_INTEGER dlibMove, DWORD dwOrigin, ULARGE_INTEGER __RPC_FAR *plibNewPosition);
 
-                virtual HRESULT __stdcall SetSize(ULARGE_INTEGER libNewSize);
+                virtual HRESULT SetSize(ULARGE_INTEGER libNewSize);
 
-                virtual  HRESULT __stdcall CopyTo(IStream __RPC_FAR *pstm, ULARGE_INTEGER cb, ULARGE_INTEGER __RPC_FAR *pcbRead, ULARGE_INTEGER __RPC_FAR *pcbWritten);
+                virtual  HRESULT CopyTo(IStream __RPC_FAR *pstm, ULARGE_INTEGER cb, ULARGE_INTEGER __RPC_FAR *pcbRead, ULARGE_INTEGER __RPC_FAR *pcbWritten);
 
-                virtual HRESULT __stdcall Commit(DWORD grfCommitFlags);
+                virtual HRESULT Commit(DWORD grfCommitFlags);
 
-                virtual HRESULT __stdcall Revert();
+                virtual HRESULT Revert();
 
-                virtual HRESULT __stdcall LockRegion(ULARGE_INTEGER libOffset, ULARGE_INTEGER cb, DWORD dwLockType);
+                virtual HRESULT LockRegion(ULARGE_INTEGER libOffset, ULARGE_INTEGER cb, DWORD dwLockType);
 
-                virtual HRESULT __stdcall UnlockRegion(ULARGE_INTEGER libOffset, ULARGE_INTEGER cb, DWORD dwLockType);
+                virtual HRESULT UnlockRegion(ULARGE_INTEGER libOffset, ULARGE_INTEGER cb, DWORD dwLockType);
 
-                virtual HRESULT __stdcall Stat(STATSTG __RPC_FAR *pstatstg, DWORD grfStatFlag);
+                virtual HRESULT Stat(STATSTG __RPC_FAR *pstatstg, DWORD grfStatFlag);
 
-                virtual HRESULT __stdcall Clone(IStream __RPC_FAR *__RPC_FAR *ppstm);
+                virtual HRESULT Clone(IStream __RPC_FAR *__RPC_FAR *ppstm);
             protected:
                 AwtDragSource*   m_parent;
 
diff --git a/src/java.desktop/windows/native/libawt/windows/awt_DnDDT.cpp b/src/java.desktop/windows/native/libawt/windows/awt_DnDDT.cpp
index b33a45a4b07..55d1ecad70f 100644
--- a/src/java.desktop/windows/native/libawt/windows/awt_DnDDT.cpp
+++ b/src/java.desktop/windows/native/libawt/windows/awt_DnDDT.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -42,9 +42,9 @@
 // forwards
 
 extern "C" {
-    DWORD __cdecl convertActionsToDROPEFFECT(jint actions);
-    jint  __cdecl convertDROPEFFECTToActions(DWORD effects);
-    DWORD __cdecl mapModsToDROPEFFECT(DWORD, DWORD);
+    DWORD convertActionsToDROPEFFECT(jint actions);
+    jint  convertDROPEFFECTToActions(DWORD effects);
+    DWORD mapModsToDROPEFFECT(DWORD, DWORD);
 } // extern "C"
 
 
@@ -95,7 +95,7 @@ AwtDropTarget::~AwtDropTarget() {
  * QueryInterface
  */
 
-HRESULT __stdcall AwtDropTarget::QueryInterface(REFIID riid, void __RPC_FAR *__RPC_FAR *ppvObject) {
+HRESULT AwtDropTarget::QueryInterface(REFIID riid, void __RPC_FAR *__RPC_FAR *ppvObject) {
     if ( IID_IUnknown == riid ||
          IID_IDropTarget == riid )
     {
@@ -111,7 +111,7 @@ HRESULT __stdcall AwtDropTarget::QueryInterface(REFIID riid, void __RPC_FAR *__R
  * AddRef
  */
 
-ULONG __stdcall AwtDropTarget::AddRef() {
+ULONG AwtDropTarget::AddRef() {
     return (ULONG)++m_refs;
 }
 
@@ -119,7 +119,7 @@ ULONG __stdcall AwtDropTarget::AddRef() {
  * Release
  */
 
-ULONG __stdcall AwtDropTarget::Release() {
+ULONG AwtDropTarget::Release() {
     int refs;
 
     if ((refs = --m_refs) == 0) delete this;
@@ -141,7 +141,7 @@ static void ScaleDown(POINT &cp, HWND m_window) {
  * DragEnter
  */
 
-HRESULT __stdcall AwtDropTarget::DragEnter(IDataObject __RPC_FAR *pDataObj, DWORD grfKeyState, POINTL pt, DWORD __RPC_FAR *pdwEffect) {
+HRESULT AwtDropTarget::DragEnter(IDataObject __RPC_FAR *pDataObj, DWORD grfKeyState, POINTL pt, DWORD __RPC_FAR *pdwEffect) {
     TRY;
     AwtToolkit::GetInstance().isDnDTargetActive = TRUE;
     if (NULL != m_pIDropTargetHelper) {
@@ -225,7 +225,7 @@ HRESULT __stdcall AwtDropTarget::DragEnter(IDataObject __RPC_FAR *pDataObj, DWOR
  * DragOver
  */
 
-HRESULT __stdcall AwtDropTarget::DragOver(DWORD grfKeyState, POINTL pt, DWORD __RPC_FAR *pdwEffect) {
+HRESULT AwtDropTarget::DragOver(DWORD grfKeyState, POINTL pt, DWORD __RPC_FAR *pdwEffect) {
     TRY;
     if (NULL != m_pIDropTargetHelper) {
         m_pIDropTargetHelper->DragOver(
@@ -282,7 +282,7 @@ HRESULT __stdcall AwtDropTarget::DragOver(DWORD grfKeyState, POINTL pt, DWORD __
  * DragLeave
  */
 
-HRESULT __stdcall AwtDropTarget::DragLeave() {
+HRESULT AwtDropTarget::DragLeave() {
     TRY_NO_VERIFY;
     if (NULL != m_pIDropTargetHelper) {
         m_pIDropTargetHelper->DragLeave();
@@ -323,7 +323,7 @@ HRESULT __stdcall AwtDropTarget::DragLeave() {
  * Drop
  */
 
-HRESULT __stdcall AwtDropTarget::Drop(IDataObject __RPC_FAR *pDataObj, DWORD grfKeyState, POINTL pt, DWORD __RPC_FAR *pdwEffect) {
+HRESULT AwtDropTarget::Drop(IDataObject __RPC_FAR *pDataObj, DWORD grfKeyState, POINTL pt, DWORD __RPC_FAR *pdwEffect) {
     TRY;
     if (NULL != m_pIDropTargetHelper) {
         m_pIDropTargetHelper->Drop(
@@ -1003,7 +1003,7 @@ jobject AwtDropTarget::GetData(jlong fmt)
  *
  */
 
-int __cdecl AwtDropTarget::_compar(const void* first, const void* second) {
+int AwtDropTarget::_compar(const void* first, const void* second) {
     FORMATETC *fp = (FORMATETC *)first;
     FORMATETC *sp = (FORMATETC *)second;
 
diff --git a/src/java.desktop/windows/native/libawt/windows/awt_DnDDT.h b/src/java.desktop/windows/native/libawt/windows/awt_DnDDT.h
index 865c016698b..fc500965315 100644
--- a/src/java.desktop/windows/native/libawt/windows/awt_DnDDT.h
+++ b/src/java.desktop/windows/native/libawt/windows/awt_DnDDT.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1997, 2009, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -49,18 +49,18 @@ class AwtDropTarget : virtual public IDropTarget {
 
         // IUnknown
 
-        virtual HRESULT __stdcall QueryInterface(REFIID riid, void __RPC_FAR *__RPC_FAR *ppvObject);
+        virtual HRESULT QueryInterface(REFIID riid, void __RPC_FAR *__RPC_FAR *ppvObject);
 
-        virtual ULONG   __stdcall AddRef(void);
-        virtual ULONG   __stdcall Release(void);
+        virtual ULONG   AddRef(void);
+        virtual ULONG   Release(void);
 
         // IDropTarget
 
-        virtual HRESULT __stdcall DragEnter(IDataObject __RPC_FAR *pDataObject, DWORD grfKeyState, POINTL pt, DWORD __RPC_FAR *pdwEffect);
-        virtual HRESULT __stdcall DragOver(DWORD grfKeyState, POINTL pt, DWORD __RPC_FAR *pdwEffect);
-        virtual HRESULT __stdcall DragLeave(void);
+        virtual HRESULT DragEnter(IDataObject __RPC_FAR *pDataObject, DWORD grfKeyState, POINTL pt, DWORD __RPC_FAR *pdwEffect);
+        virtual HRESULT DragOver(DWORD grfKeyState, POINTL pt, DWORD __RPC_FAR *pdwEffect);
+        virtual HRESULT DragLeave(void);
 
-        virtual HRESULT __stdcall Drop(IDataObject __RPC_FAR *pDataObject, DWORD grfKeyState, POINTL pt, DWORD __RPC_FAR *pdwEffect);
+        virtual HRESULT Drop(IDataObject __RPC_FAR *pDataObject, DWORD grfKeyState, POINTL pt, DWORD __RPC_FAR *pdwEffect);
 
         // AwtDropTarget
 
@@ -186,7 +186,7 @@ class AwtDropTarget : virtual public IDropTarget {
 
         static const unsigned int CACHE_INCR;
 
-        static int __cdecl _compar(const void *, const void *);
+        static int _compar(const void *, const void *);
 };
 
 
diff --git a/src/java.desktop/windows/native/libawt/windows/awt_Toolkit.cpp b/src/java.desktop/windows/native/libawt/windows/awt_Toolkit.cpp
index 5d7171addb4..b467a685516 100644
--- a/src/java.desktop/windows/native/libawt/windows/awt_Toolkit.cpp
+++ b/src/java.desktop/windows/native/libawt/windows/awt_Toolkit.cpp
@@ -2195,7 +2195,7 @@ bool AwtToolkit::PreloadThread::Terminate(bool wrongThread)
     return true;
 }
 
-bool AwtToolkit::PreloadThread::InvokeAndTerminate(void(_cdecl *fn)(void *), void *param)
+bool AwtToolkit::PreloadThread::InvokeAndTerminate(void(*fn)(void *), void *param)
 {
     CriticalSection::Lock lock(threadLock);
 
@@ -2225,7 +2225,7 @@ unsigned WINAPI AwtToolkit::PreloadThread::StaticThreadProc(void *param)
 
 unsigned AwtToolkit::PreloadThread::ThreadProc()
 {
-    void(_cdecl *_execFunc)(void *) = NULL;
+    void(*_execFunc)(void *) = NULL;
     void *_execParam = NULL;
     bool _wrongThread = false;
 
diff --git a/src/java.desktop/windows/native/libawt/windows/awt_Toolkit.h b/src/java.desktop/windows/native/libawt/windows/awt_Toolkit.h
index 4a4b2bdcb3f..29485c8ba41 100644
--- a/src/java.desktop/windows/native/libawt/windows/awt_Toolkit.h
+++ b/src/java.desktop/windows/native/libawt/windows/awt_Toolkit.h
@@ -612,7 +612,7 @@ public:
         //   false means termination on the application shutdown;
         // wrongThread is used as reInit parameter for action cleanup.
         bool Terminate(bool wrongThread);
-        bool InvokeAndTerminate(void(_cdecl *fn)(void *), void *param);
+        bool InvokeAndTerminate(void(*fn)(void *), void *param);
 
         // waits for the thread completion;
         // use the method after Terminate() only if Terminate() returned true
@@ -664,7 +664,7 @@ public:
 
         // function/param to invoke (InvokeAndTerminate)
         // if execFunc == NULL => just terminate
-        void(_cdecl *execFunc)(void *);
+        void(*execFunc)(void *);
         void *execParam;
 
         // action chain
diff --git a/src/java.desktop/windows/native/libawt/windows/awt_new.cpp b/src/java.desktop/windows/native/libawt/windows/awt_new.cpp
index 1f61a37cfc7..e9cdd95fbb4 100644
--- a/src/java.desktop/windows/native/libawt/windows/awt_new.cpp
+++ b/src/java.desktop/windows/native/libawt/windows/awt_new.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2005, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -120,7 +120,7 @@ void *safe_Realloc(void *memblock, size_t size) {
 // std::bad_alloc in an out of memory situation. Instead, VC++ 5.0 returns 0.
 //
 // This function can be safely removed when the problem is corrected.
-void * CDECL operator new(size_t size) {
+void * operator new(size_t size) {
     return safe_Malloc(size);
 }
 #endif
@@ -228,7 +228,7 @@ void *safe_Realloc_outofmem(void *memblock, size_t size, const char *file,
     return safe_Realloc(memblock, size);
 }
 
-void * CDECL operator new(size_t size, const char *file, int line) {
+void * operator new(size_t size, const char *file, int line) {
     rand_alloc_fail(file, line);
     return operator new(size);
 }
diff --git a/src/java.desktop/windows/native/libjsound/PLATFORM_API_WinOS_Charset_Util.h b/src/java.desktop/windows/native/libjsound/PLATFORM_API_WinOS_Charset_Util.h
index 092c5e43e12..7ddd11a4aef 100644
--- a/src/java.desktop/windows/native/libjsound/PLATFORM_API_WinOS_Charset_Util.h
+++ b/src/java.desktop/windows/native/libjsound/PLATFORM_API_WinOS_Charset_Util.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2017, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -33,9 +33,9 @@ extern "C" {
 #endif
 
 // NOTE: It's a caller responbility to free the allocated memory using delete[], just like in UnicodeToUTF8AndCopy function
-LPSTR _cdecl UnicodeToUTF8(const LPCWSTR lpAnsiStr);
+LPSTR UnicodeToUTF8(const LPCWSTR lpAnsiStr);
 
-void _cdecl UnicodeToUTF8AndCopy(LPSTR dest, LPCWSTR src, SIZE_T maxLength);
+void UnicodeToUTF8AndCopy(LPSTR dest, LPCWSTR src, SIZE_T maxLength);
 
 #ifdef __cplusplus
 }
diff --git a/src/java.desktop/windows/native/libjsound/PLATFORM_API_WinOS_DirectSound.cpp b/src/java.desktop/windows/native/libjsound/PLATFORM_API_WinOS_DirectSound.cpp
index 1ca8d7a6676..e04b2351b15 100644
--- a/src/java.desktop/windows/native/libjsound/PLATFORM_API_WinOS_DirectSound.cpp
+++ b/src/java.desktop/windows/native/libjsound/PLATFORM_API_WinOS_DirectSound.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -469,7 +469,7 @@ protected:
     } static data;
 
     /* StartThread function */
-    static DWORD WINAPI __stdcall ThreadProc(void *param);
+    static DWORD WINAPI ThreadProc(void *param);
 };
 
 /* StartBufferHelper class implementation
@@ -499,7 +499,7 @@ DS_StartBufferHelper::Data::~Data() {
     // - Windows will do during process shutdown
 }
 
-DWORD WINAPI __stdcall DS_StartBufferHelper::ThreadProc(void *param)
+DWORD WINAPI DS_StartBufferHelper::ThreadProc(void *param)
 {
     ::CoInitialize(NULL);
     while (1) {
diff --git a/src/java.desktop/windows/native/libjsound/PLATFORM_API_WinOS_MidiIn.cpp b/src/java.desktop/windows/native/libjsound/PLATFORM_API_WinOS_MidiIn.cpp
index 91e1a50c661..12cfa82fda8 100644
--- a/src/java.desktop/windows/native/libjsound/PLATFORM_API_WinOS_MidiIn.cpp
+++ b/src/java.desktop/windows/native/libjsound/PLATFORM_API_WinOS_MidiIn.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -165,7 +165,7 @@ protected:
     } static data;
 
     /* StartThread function */
-    static DWORD WINAPI __stdcall ThreadProc(void *param);
+    static DWORD WINAPI ThreadProc(void *param);
 };
 
 /* MidiIn_OpenHelper class implementation
@@ -195,7 +195,7 @@ MidiIn_OpenHelper::Data::~Data() {
     // - Windows will do during process shutdown
 }
 
-DWORD WINAPI __stdcall MidiIn_OpenHelper::ThreadProc(void *param) {
+DWORD WINAPI MidiIn_OpenHelper::ThreadProc(void *param) {
     while (1) {
         // wait for something to do
         ::WaitForSingleObject(data.doEvent, INFINITE);
diff --git a/src/jdk.accessibility/windows/native/libjabsysinfo/AccessBridgeSysInfo.cpp b/src/jdk.accessibility/windows/native/libjabsysinfo/AccessBridgeSysInfo.cpp
deleted file mode 100644
index 072093466a6..00000000000
--- a/src/jdk.accessibility/windows/native/libjabsysinfo/AccessBridgeSysInfo.cpp
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
- * Copyright (c) 2014, 2015, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.  Oracle designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Oracle in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- */
-
-#include <exception>
-#include <stdexcept>
-#include <jni.h>
-#include <windows.h>
-#include <WinDef.h>
-
-extern "C" {
-
-BOOL WINAPI DllMain(HINSTANCE hinstDll, DWORD fdwReason, LPVOID lpvReserved) {
-    return TRUE;
-}
-
-// Determine bitness of Win OS
-JNIEXPORT jboolean JNICALL
-Java_com_sun_java_accessibility_internal_AccessBridge_isSysWow(JNIEnv *env, jobject callingObj) {
-    BOOL bIsWow64 = FALSE;
-    typedef BOOL (WINAPI *LPFN_ISWOW64PROCESS) (HANDLE, PBOOL);
-
-    LPFN_ISWOW64PROCESS fnIsWow64Process =
-        (LPFN_ISWOW64PROCESS)GetProcAddress(GetModuleHandle(TEXT("kernel32")), "IsWow64Process");
-
-    if (fnIsWow64Process != NULL) {
-        if (!fnIsWow64Process(GetCurrentProcess(), &bIsWow64)) {
-            throw std::runtime_error("fnIsWow64Process() failed");
-        }
-    }
-
-    return bIsWow64 ? JNI_TRUE : JNI_FALSE;
-}
-
-}
diff --git a/src/jdk.accessibility/windows/native/libjavaaccessbridge/AccessBridgeATInstance.cpp b/src/jdk.accessibility/windows/native/libjavaaccessbridge/AccessBridgeATInstance.cpp
index 935c0180635..64dd32f7261 100644
--- a/src/jdk.accessibility/windows/native/libjavaaccessbridge/AccessBridgeATInstance.cpp
+++ b/src/jdk.accessibility/windows/native/libjavaaccessbridge/AccessBridgeATInstance.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2005, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -141,8 +141,8 @@ typedef struct EVENT_STRUCT
 
 
 #include <process.h>
-#define THREAD_PROC unsigned int __stdcall
-typedef unsigned int (__stdcall *THREAD_ROUTINE)(LPVOID lpThreadParameter);
+#define THREAD_PROC unsigned int
+typedef unsigned int (*THREAD_ROUTINE)(LPVOID lpThreadParameter);
 
 static HANDLE BeginThread(THREAD_ROUTINE thread_func,DWORD *id,DWORD param)
 {
diff --git a/src/jdk.attach/windows/native/libattach/VirtualMachineImpl.c b/src/jdk.attach/windows/native/libattach/VirtualMachineImpl.c
index 7a436ef85c2..dc1b0f6e79a 100644
--- a/src/jdk.attach/windows/native/libattach/VirtualMachineImpl.c
+++ b/src/jdk.attach/windows/native/libattach/VirtualMachineImpl.c
@@ -76,8 +76,7 @@ typedef struct {
    GetModuleHandleFunc _GetModuleHandle;
    GetProcAddressFunc _GetProcAddress;
    char jvmLib[MAX_LIBNAME_LENGTH];         /* "jvm.dll" */
-   char func1[MAX_FUNC_LENGTH];
-   char func2[MAX_FUNC_LENGTH];
+   char func[MAX_FUNC_LENGTH];
    char func_v2[MAX_FUNC_LENGTH];
    char cmd[MAX_CMD_LENGTH + 1];            /* "load", "dump", ...      */
    char arg[MAX_ARGS][MAX_ARG_LENGTH + 1];  /* arguments to command     */
@@ -113,10 +112,7 @@ DWORD WINAPI jvm_attach_thread_func(DataBlock *pData)
     }
 
     if (pData->version == 1) {
-        EnqueueOperationFunc addr = (EnqueueOperationFunc)(pData->_GetProcAddress(h, pData->func1));
-        if (addr == NULL) {
-            addr = (EnqueueOperationFunc)(pData->_GetProcAddress(h, pData->func2));
-        }
+        EnqueueOperationFunc addr = (EnqueueOperationFunc)(pData->_GetProcAddress(h, pData->func));
         if (addr == NULL) {
             return ERR_GET_ENQUEUE_FUNC_FAIL;
         }
@@ -231,24 +227,17 @@ JNIEXPORT jlong JNICALL Java_sun_tools_attach_VirtualMachineImpl_openProcess
     }
 
     /*
-     * On Windows 64-bit we need to handle 32-bit tools trying to attach to 64-bit
-     * processes (and visa versa). X-architecture attaching is currently not supported
-     * by this implementation.
+     * On Windows we need to handle 64-bit tools trying to attach to 32-bit
+     * processes, which is currently not supported by this implementation.
      */
     if (_IsWow64Process != NULL) {
-        BOOL isCurrent32bit, isTarget32bit;
-        (*_IsWow64Process)(GetCurrentProcess(), &isCurrent32bit);
+        BOOL isTarget32bit;
         (*_IsWow64Process)(hProcess, &isTarget32bit);
 
-        if (isCurrent32bit != isTarget32bit) {
+        if (isTarget32bit) {
             CloseHandle(hProcess);
-            #ifdef _WIN64
-              JNU_ThrowByName(env, "com/sun/tools/attach/AttachNotSupportedException",
-                  "Unable to attach to 32-bit process running under WOW64");
-            #else
-              JNU_ThrowByName(env, "com/sun/tools/attach/AttachNotSupportedException",
-                  "Unable to attach to 64-bit process");
-            #endif
+            JNU_ThrowByName(env, "com/sun/tools/attach/AttachNotSupportedException",
+                "Unable to attach to 32-bit process running under WOW64");
         }
     }
 
@@ -451,8 +440,7 @@ JNIEXPORT void JNICALL Java_sun_tools_attach_VirtualMachineImpl_enqueue
     data._GetProcAddress = _GetProcAddress;
 
     strcpy(data.jvmLib, "jvm");
-    strcpy(data.func1, "JVM_EnqueueOperation");
-    strcpy(data.func2, "_JVM_EnqueueOperation@20");
+    strcpy(data.func, "JVM_EnqueueOperation");
     strcpy(data.func_v2, "JVM_EnqueueOperation_v2");
 
     /*
diff --git a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/WindbgCDebugger.java b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/WindbgCDebugger.java
index 5d6b58fa085..64bdb8c1c72 100644
--- a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/WindbgCDebugger.java
+++ b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/WindbgCDebugger.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -28,9 +28,7 @@ import java.io.*;
 import java.util.*;
 import sun.jvm.hotspot.debugger.*;
 import sun.jvm.hotspot.debugger.cdbg.*;
-import sun.jvm.hotspot.debugger.x86.*;
 import sun.jvm.hotspot.debugger.amd64.*;
-import sun.jvm.hotspot.debugger.windows.x86.*;
 import sun.jvm.hotspot.debugger.windows.amd64.*;
 import sun.jvm.hotspot.utilities.AddressOps;
 
@@ -69,14 +67,7 @@ class WindbgCDebugger implements CDebugger {
   }
 
   public CFrame topFrameForThread(ThreadProxy thread) throws DebuggerException {
-    if (dbg.getCPU().equals("x86")) {
-      X86ThreadContext context = (X86ThreadContext) thread.getContext();
-      Address ebp = context.getRegisterAsAddress(X86ThreadContext.EBP);
-      if (ebp == null) return null;
-      Address pc  = context.getRegisterAsAddress(X86ThreadContext.EIP);
-      if (pc == null) return null;
-      return new WindowsX86CFrame(dbg, ebp, pc);
-    } else if (dbg.getCPU().equals("amd64")) {
+    if (dbg.getCPU().equals("amd64")) {
       AMD64ThreadContext context = (AMD64ThreadContext) thread.getContext();
       Address rbp = context.getRegisterAsAddress(AMD64ThreadContext.RBP);
       if (rbp == null) return null;
diff --git a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/WindbgDebuggerLocal.java b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/WindbgDebuggerLocal.java
index f082b7e52c6..07704671fd4 100644
--- a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/WindbgDebuggerLocal.java
+++ b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/WindbgDebuggerLocal.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2002, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2002, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -30,10 +30,8 @@ import java.util.*;
 import sun.jvm.hotspot.debugger.*;
 import sun.jvm.hotspot.debugger.aarch64.*;
 import sun.jvm.hotspot.debugger.amd64.*;
-import sun.jvm.hotspot.debugger.x86.*;
 import sun.jvm.hotspot.debugger.windbg.aarch64.*;
 import sun.jvm.hotspot.debugger.windbg.amd64.*;
-import sun.jvm.hotspot.debugger.windbg.x86.*;
 import sun.jvm.hotspot.debugger.win32.coff.*;
 import sun.jvm.hotspot.debugger.cdbg.*;
 import sun.jvm.hotspot.debugger.cdbg.basic.BasicDebugEvent;
@@ -100,9 +98,7 @@ public class WindbgDebuggerLocal extends DebuggerBase implements WindbgDebugger
                                   machDesc.supports32bitAlignmentOf64bitTypes());
 
     String cpu = PlatformInfo.getCPU();
-    if (cpu.equals("x86")) {
-       threadFactory = new WindbgX86ThreadFactory(this);
-    } else if (cpu.equals("amd64")) {
+    if (cpu.equals("amd64")) {
        threadFactory = new WindbgAMD64ThreadFactory(this);
     } else if (cpu.equals("aarch64")) {
       threadFactory = new WindbgAARCH64ThreadFactory(this);
diff --git a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/x86/WindbgX86Thread.java b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/x86/WindbgX86Thread.java
deleted file mode 100644
index 7a9de861f9a..00000000000
--- a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/x86/WindbgX86Thread.java
+++ /dev/null
@@ -1,92 +0,0 @@
-/*
- * Copyright (c) 2002, 2022, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-
-package sun.jvm.hotspot.debugger.windbg.x86;
-
-import sun.jvm.hotspot.debugger.*;
-import sun.jvm.hotspot.debugger.windbg.*;
-
-class WindbgX86Thread implements ThreadProxy {
-  private WindbgDebugger debugger;
-  private long           sysId;
-  private boolean        gotID;
-  private long           id;
-
-  // The address argument must be the address of OSThread::_thread_id
-  WindbgX86Thread(WindbgDebugger debugger, Address addr) {
-    this.debugger = debugger;
-    this.sysId    = addr.getCIntegerAt(0, 4, true);
-    gotID         = false;
-  }
-
-  WindbgX86Thread(WindbgDebugger debugger, long sysId) {
-    this.debugger = debugger;
-    this.sysId    = sysId;
-    gotID         = false;
-  }
-
-  public ThreadContext getContext() throws IllegalThreadStateException {
-    long[] data = debugger.getThreadIntegerRegisterSet(getThreadID());
-    WindbgX86ThreadContext context = new WindbgX86ThreadContext(debugger);
-    for (int i = 0; i < data.length; i++) {
-      context.setRegister(i, data[i]);
-    }
-    return context;
-  }
-
-  public boolean canSetContext() throws DebuggerException {
-    return false;
-  }
-
-  public void setContext(ThreadContext thrCtx)
-    throws IllegalThreadStateException, DebuggerException {
-    throw new DebuggerException("Unimplemented");
-  }
-
-  public boolean equals(Object obj) {
-    if (!(obj instanceof WindbgX86Thread other)) {
-      return false;
-    }
-
-    return (other.getThreadID() == getThreadID());
-  }
-
-  public int hashCode() {
-    return Long.hashCode(getThreadID());
-  }
-
-  public String toString() {
-    return Long.toString(getThreadID());
-  }
-
-  /** Retrieves the thread ID of this thread by examining the Thread
-      Information Block. */
-  private long getThreadID() {
-    if (!gotID) {
-       id = debugger.getThreadIdFromSysId(sysId);
-    }
-
-    return id;
-  }
-}
diff --git a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/x86/WindbgX86ThreadContext.java b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/x86/WindbgX86ThreadContext.java
deleted file mode 100644
index 4135653b0b2..00000000000
--- a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/x86/WindbgX86ThreadContext.java
+++ /dev/null
@@ -1,46 +0,0 @@
-/*
- * Copyright (c) 2002, 2003, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-
-package sun.jvm.hotspot.debugger.windbg.x86;
-
-import sun.jvm.hotspot.debugger.*;
-import sun.jvm.hotspot.debugger.x86.*;
-import sun.jvm.hotspot.debugger.windbg.*;
-
-class WindbgX86ThreadContext extends X86ThreadContext {
-  private WindbgDebugger debugger;
-
-  public WindbgX86ThreadContext(WindbgDebugger debugger) {
-    super();
-    this.debugger = debugger;
-  }
-
-  public void setRegisterAsAddress(int index, Address value) {
-    setRegister(index, debugger.getAddressValue(value));
-  }
-
-  public Address getRegisterAsAddress(int index) {
-    return debugger.newAddress(getRegister(index));
-  }
-}
diff --git a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/x86/WindbgX86ThreadFactory.java b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/x86/WindbgX86ThreadFactory.java
deleted file mode 100644
index 8ca83af2c49..00000000000
--- a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windbg/x86/WindbgX86ThreadFactory.java
+++ /dev/null
@@ -1,44 +0,0 @@
-/*
- * Copyright (c) 2003, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-
-package sun.jvm.hotspot.debugger.windbg.x86;
-
-import sun.jvm.hotspot.debugger.*;
-import sun.jvm.hotspot.debugger.windbg.*;
-
-public class WindbgX86ThreadFactory implements WindbgThreadFactory {
-  private WindbgDebugger debugger;
-
-  public WindbgX86ThreadFactory(WindbgDebugger debugger) {
-    this.debugger = debugger;
-  }
-
-  public ThreadProxy createThreadWrapper(Address threadIdentifierAddr) {
-    return new WindbgX86Thread(debugger, threadIdentifierAddr);
-  }
-
-  public ThreadProxy createThreadWrapper(long id) {
-    return new WindbgX86Thread(debugger, id);
-  }
-}
diff --git a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windows/x86/WindowsX86CFrame.java b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windows/x86/WindowsX86CFrame.java
deleted file mode 100644
index 1d5e015e888..00000000000
--- a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/debugger/windows/x86/WindowsX86CFrame.java
+++ /dev/null
@@ -1,88 +0,0 @@
-/*
- * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-
-package sun.jvm.hotspot.debugger.windows.x86;
-
-import sun.jvm.hotspot.debugger.*;
-import sun.jvm.hotspot.debugger.x86.*;
-import sun.jvm.hotspot.debugger.cdbg.*;
-import sun.jvm.hotspot.debugger.cdbg.basic.*;
-import sun.jvm.hotspot.debugger.windbg.*;
-
-public class WindowsX86CFrame extends BasicCFrame {
-  private Address ebp;
-  private Address pc;
-
-  private static final int ADDRESS_SIZE = 4;
-
-  /** Constructor for topmost frame */
-  public WindowsX86CFrame(WindbgDebugger dbg, Address ebp, Address pc) {
-    super(dbg.getCDebugger());
-    this.ebp = ebp;
-    this.pc  = pc;
-    this.dbg = dbg;
-  }
-
-  public CFrame sender(ThreadProxy thread) {
-    X86ThreadContext context = (X86ThreadContext) thread.getContext();
-    /*
-     * Native code fills in the stack pointer register value using index
-     * X86ThreadContext.SP.
-     * See file sawindbg.cpp macro REG_INDEX(x).
-     *
-     * Be sure to use SP, or UESP which is aliased to SP in Java code,
-     * for the frame pointer validity check.
-     */
-    Address esp = context.getRegisterAsAddress(X86ThreadContext.SP);
-
-    if ( (ebp == null) || ebp.lessThan(esp) ) {
-      return null;
-    }
-
-    // Check alignment of ebp
-    if ( dbg.getAddressValue(ebp) % ADDRESS_SIZE != 0) {
-        return null;
-    }
-
-    Address nextEBP = ebp.getAddressAt( 0 * ADDRESS_SIZE);
-    if (nextEBP == null || nextEBP.lessThanOrEqual(ebp)) {
-      return null;
-    }
-    Address nextPC  = ebp.getAddressAt( 1 * ADDRESS_SIZE);
-    if (nextPC == null) {
-      return null;
-    }
-    return new WindowsX86CFrame(dbg, nextEBP, nextPC);
-  }
-
-  public Address pc() {
-    return pc;
-  }
-
-  public Address localVariableBase() {
-    return ebp;
-  }
-
-  private WindbgDebugger dbg;
-}
diff --git a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/Threads.java b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/Threads.java
index 6e347858154..e8eacbe756f 100644
--- a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/Threads.java
+++ b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/Threads.java
@@ -28,7 +28,6 @@ import java.util.*;
 
 import sun.jvm.hotspot.debugger.*;
 import sun.jvm.hotspot.types.*;
-import sun.jvm.hotspot.runtime.win32_x86.Win32X86JavaThreadPDAccess;
 import sun.jvm.hotspot.runtime.win32_amd64.Win32AMD64JavaThreadPDAccess;
 import sun.jvm.hotspot.runtime.win32_aarch64.Win32AARCH64JavaThreadPDAccess;
 import sun.jvm.hotspot.runtime.linux_x86.LinuxX86JavaThreadPDAccess;
@@ -98,9 +97,7 @@ public class Threads {
         access = null;
         // FIXME: find the platform specific PD class by reflection?
         if (os.equals("win32")) {
-            if (cpu.equals("x86")) {
-                access =  new Win32X86JavaThreadPDAccess();
-            } else if (cpu.equals("amd64")) {
+            if (cpu.equals("amd64")) {
                 access =  new Win32AMD64JavaThreadPDAccess();
             } else if (cpu.equals("aarch64")) {
                 access =  new Win32AARCH64JavaThreadPDAccess();
diff --git a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/win32_x86/Win32X86JavaThreadPDAccess.java b/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/win32_x86/Win32X86JavaThreadPDAccess.java
deleted file mode 100644
index 93dd66e1acf..00000000000
--- a/src/jdk.hotspot.agent/share/classes/sun/jvm/hotspot/runtime/win32_x86/Win32X86JavaThreadPDAccess.java
+++ /dev/null
@@ -1,138 +0,0 @@
-/*
- * Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
- * or visit www.oracle.com if you need additional information or have any
- * questions.
- *
- */
-
-package sun.jvm.hotspot.runtime.win32_x86;
-
-import java.io.*;
-import java.util.*;
-import sun.jvm.hotspot.debugger.*;
-import sun.jvm.hotspot.debugger.x86.*;
-import sun.jvm.hotspot.runtime.*;
-import sun.jvm.hotspot.runtime.x86.*;
-import sun.jvm.hotspot.types.*;
-import sun.jvm.hotspot.utilities.*;
-import sun.jvm.hotspot.utilities.Observable;
-import sun.jvm.hotspot.utilities.Observer;
-
-/** This class is only public to allow using the VMObjectFactory to
-    instantiate these.
-*/
-
-public class Win32X86JavaThreadPDAccess implements JavaThreadPDAccess {
-  private static AddressField  lastJavaFPField;
-  private static AddressField  osThreadField;
-
-  // Field from OSThread
-  private static Field         threadIdField;
-
-  // This is currently unneeded but is being kept in case we change
-  // the currentFrameGuess algorithm
-  private static final long GUESS_SCAN_RANGE = 128 * 1024;
-
-  static {
-    VM.registerVMInitializedObserver(new Observer() {
-        public void update(Observable o, Object data) {
-          initialize(VM.getVM().getTypeDataBase());
-        }
-      });
-  }
-
-  private static synchronized void initialize(TypeDataBase db) {
-    Type type = db.lookupType("JavaThread");
-    Type anchorType = db.lookupType("JavaFrameAnchor");
-    lastJavaFPField         = anchorType.getAddressField("_last_Java_fp");
-    osThreadField           = type.getAddressField("_osthread");
-
-    type = db.lookupType("OSThread");
-    threadIdField = type.getField("_thread_id");
-  }
-
-  public Address getLastJavaFP(Address addr) {
-    return lastJavaFPField.getValue(addr.addOffsetTo(sun.jvm.hotspot.runtime.JavaThread.getAnchorField().getOffset()));
-  }
-
-  public Address getLastJavaPC(Address addr) {
-    return null;
-  }
-
-  public Address getBaseOfStackPointer(Address addr) {
-    return null;
-  }
-
-  public Frame getLastFramePD(JavaThread thread, Address addr) {
-    Address fp = thread.getLastJavaFP();
-    if (fp == null) {
-      return null; // no information
-    }
-    Address pc =  thread.getLastJavaPC();
-    if ( pc != null ) {
-      return new X86Frame(thread.getLastJavaSP(), fp, pc);
-    } else {
-      return new X86Frame(thread.getLastJavaSP(), fp);
-    }
-  }
-
-  public RegisterMap newRegisterMap(JavaThread thread, boolean updateMap) {
-    return new X86RegisterMap(thread, updateMap);
-  }
-
-  public Frame getCurrentFrameGuess(JavaThread thread, Address addr) {
-    ThreadProxy t = getThreadProxy(addr);
-    X86ThreadContext context = (X86ThreadContext) t.getContext();
-    X86CurrentFrameGuess guesser = new X86CurrentFrameGuess(context, thread);
-    if (!guesser.run(GUESS_SCAN_RANGE)) {
-      return null;
-    }
-    if (guesser.getPC() == null) {
-      return new X86Frame(guesser.getSP(), guesser.getFP());
-    } else {
-      return new X86Frame(guesser.getSP(), guesser.getFP(), guesser.getPC());
-    }
-  }
-
-  public void printThreadIDOn(Address addr, PrintStream tty) {
-    tty.print(getThreadProxy(addr));
-  }
-
-  public void printInfoOn(Address threadAddr, PrintStream tty) {
-  }
-
-  public Address getLastSP(Address addr) {
-    ThreadProxy t = getThreadProxy(addr);
-    X86ThreadContext context = (X86ThreadContext) t.getContext();
-    return context.getRegisterAsAddress(X86ThreadContext.ESP);
-  }
-
-  public ThreadProxy getThreadProxy(Address addr) {
-    // Addr is the address of the JavaThread.
-    // Fetch the OSThread (for now and for simplicity, not making a
-    // separate "OSThread" class in this package)
-    Address osThreadAddr = osThreadField.getValue(addr);
-    // Get the address of the thread_id within the OSThread
-    Address threadIdAddr =
-      osThreadAddr.addOffsetTo(threadIdField.getOffset());
-    JVMDebugger debugger = VM.getVM().getDebugger();
-    return debugger.getThreadForIdentifierAddress(threadIdAddr);
-  }
-}
diff --git a/src/jdk.hotspot.agent/windows/native/libsaproc/sawindbg.cpp b/src/jdk.hotspot.agent/windows/native/libsaproc/sawindbg.cpp
index de3c45d00d2..1ecac8ac97a 100644
--- a/src/jdk.hotspot.agent/windows/native/libsaproc/sawindbg.cpp
+++ b/src/jdk.hotspot.agent/windows/native/libsaproc/sawindbg.cpp
@@ -30,10 +30,7 @@
 
 #include "sun_jvm_hotspot_debugger_windbg_WindbgDebuggerLocal.h"
 
-#ifdef _M_IX86
-  #include "sun_jvm_hotspot_debugger_x86_X86ThreadContext.h"
-  #define NPRGREG sun_jvm_hotspot_debugger_x86_X86ThreadContext_NPRGREG
-#elif _M_AMD64
+#ifdef _M_AMD64
   #include "sun_jvm_hotspot_debugger_amd64_AMD64ThreadContext.h"
   #define NPRGREG sun_jvm_hotspot_debugger_amd64_AMD64ThreadContext_NPRGREG
 #elif _M_ARM64
@@ -560,39 +557,7 @@ static bool addThreads(JNIEnv* env, jobject obj) {
     memset(&context, 0, sizeof(CONTEXT));
 
 #undef REG_INDEX
-#ifdef _M_IX86
-    #define REG_INDEX(x) sun_jvm_hotspot_debugger_x86_X86ThreadContext_##x
-
-    context.ContextFlags = CONTEXT_FULL | CONTEXT_DEBUG_REGISTERS;
-    ptrIDebugAdvanced->GetThreadContext(&context, sizeof(CONTEXT));
-
-    ptrRegs[REG_INDEX(GS)]  = context.SegGs;
-    ptrRegs[REG_INDEX(FS)]  = context.SegFs;
-    ptrRegs[REG_INDEX(ES)]  = context.SegEs;
-    ptrRegs[REG_INDEX(DS)]  = context.SegDs;
-
-    ptrRegs[REG_INDEX(EDI)] = context.Edi;
-    ptrRegs[REG_INDEX(ESI)] = context.Esi;
-    ptrRegs[REG_INDEX(EBX)] = context.Ebx;
-    ptrRegs[REG_INDEX(EDX)] = context.Edx;
-    ptrRegs[REG_INDEX(ECX)] = context.Ecx;
-    ptrRegs[REG_INDEX(EAX)] = context.Eax;
-
-    ptrRegs[REG_INDEX(FP)] = context.Ebp;
-    ptrRegs[REG_INDEX(PC)] = context.Eip;
-    ptrRegs[REG_INDEX(CS)]  = context.SegCs;
-    ptrRegs[REG_INDEX(EFL)] = context.EFlags;
-    ptrRegs[REG_INDEX(SP)] = context.Esp;
-    ptrRegs[REG_INDEX(SS)]  = context.SegSs;
-
-    ptrRegs[REG_INDEX(DR0)] = context.Dr0;
-    ptrRegs[REG_INDEX(DR1)] = context.Dr1;
-    ptrRegs[REG_INDEX(DR2)] = context.Dr2;
-    ptrRegs[REG_INDEX(DR3)] = context.Dr3;
-    ptrRegs[REG_INDEX(DR6)] = context.Dr6;
-    ptrRegs[REG_INDEX(DR7)] = context.Dr7;
-
-#elif _M_AMD64
+#ifdef _M_AMD64
     #define REG_INDEX(x) sun_jvm_hotspot_debugger_amd64_AMD64ThreadContext_##x
 
     context.ContextFlags = CONTEXT_FULL | CONTEXT_DEBUG_REGISTERS;
diff --git a/src/jdk.jdwp.agent/share/native/libjdwp/transport.c b/src/jdk.jdwp.agent/share/native/libjdwp/transport.c
index f67e9da47ea..b19afd972b7 100644
--- a/src/jdk.jdwp.agent/share/native/libjdwp/transport.c
+++ b/src/jdk.jdwp.agent/share/native/libjdwp/transport.c
@@ -105,13 +105,6 @@ findTransportOnLoad(void *handle)
     if (handle == NULL) {
         return onLoad;
     }
-#if defined(_WIN32) && !defined(_WIN64)
-    onLoad = (jdwpTransport_OnLoad_t)
-                 dbgsysFindLibraryEntry(handle, "_jdwpTransport_OnLoad@16");
-    if (onLoad != NULL) {
-        return onLoad;
-    }
-#endif
     onLoad = (jdwpTransport_OnLoad_t)
                  dbgsysFindLibraryEntry(handle, "jdwpTransport_OnLoad");
     return onLoad;
diff --git a/src/jdk.jpackage/share/native/applauncher/JvmLauncher.cpp b/src/jdk.jpackage/share/native/applauncher/JvmLauncher.cpp
index db01cd164bc..5997b80fa5f 100644
--- a/src/jdk.jpackage/share/native/applauncher/JvmLauncher.cpp
+++ b/src/jdk.jpackage/share/native/applauncher/JvmLauncher.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -34,12 +34,6 @@
 #include "Toolbox.h"
 #include "ErrorHandling.h"
 
-#if defined(_WIN32) && !defined(_WIN64)
-#define LAUNCH_FUNC "_JLI_Launch@56"
-#else
-#define LAUNCH_FUNC "JLI_Launch"
-#endif
-
 Jvm::Jvm() {
     LOG_TRACE(tstrings::any() << "Jvm(" << this << ")::Jvm()");
 }
@@ -206,7 +200,7 @@ void Jvm::launch() {
 
     LOG_TRACE(tstrings::any() << "JVM library: \"" << jvmPath << "\"");
 
-    DllFunction<void*> func(Dll(jvmPath), LAUNCH_FUNC);
+    DllFunction<void*> func(Dll(jvmPath), "JLI_Launch");
 
     int exitStatus = jvmLauncherStartJvm(jld.get(), func.operator void*());
 
diff --git a/src/jdk.jpackage/windows/native/applauncher/WinLauncher.cpp b/src/jdk.jpackage/windows/native/applauncher/WinLauncher.cpp
index 5323643cddd..fe59cd94b84 100644
--- a/src/jdk.jpackage/windows/native/applauncher/WinLauncher.cpp
+++ b/src/jdk.jpackage/windows/native/applauncher/WinLauncher.cpp
@@ -339,13 +339,13 @@ void launchApp() {
 
 #ifndef JP_LAUNCHERW
 
-int __cdecl  wmain() {
+int wmain() {
     return app::launch(std::nothrow, launchApp);
 }
 
 #else
 
-int __stdcall wWinMain(HINSTANCE, HINSTANCE, LPWSTR, int) {
+int wWinMain(HINSTANCE, HINSTANCE, LPWSTR, int) {
     return app::wlaunch(std::nothrow, launchApp);
 }
 
diff --git a/src/jdk.jpackage/windows/native/common/MsiCA.h b/src/jdk.jpackage/windows/native/common/MsiCA.h
index 67dfde82c91..72dfa7607b0 100644
--- a/src/jdk.jpackage/windows/native/common/MsiCA.h
+++ b/src/jdk.jpackage/windows/native/common/MsiCA.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2022, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -267,7 +267,7 @@ private:
 //
 #define JP_CA_BASE(name, ca_type) \
     static void name ## Body(ca_type&); \
-    extern "C" UINT __stdcall name(MSIHANDLE hInstall) { \
+    extern "C" UINT name(MSIHANDLE hInstall) { \
         __pragma(comment(linker, "/EXPORT:" __FUNCTION__ "=" __FUNCDNAME__)); \
         const msi::MsiLogTrigger logTrigger(hInstall); \
         JP_DEBUG_BREAK(JP_CA_DEBUG_BREAK, name); \
@@ -286,13 +286,9 @@ private:
 #define JP_DEFERRED_CA(name) JP_CA_BASE(name, msi::DeferredCA)
 
 #define JP_CA_DECLARE(name) \
-    extern "C" UINT __stdcall name(MSIHANDLE); \
+    extern "C" UINT name(MSIHANDLE); \
     __pragma(comment(linker, "/INCLUDE:" JP_CA_MANGLED_NAME(name)))
 
-#ifdef _WIN64
-    #define JP_CA_MANGLED_NAME(name) #name
-#else
-    #define JP_CA_MANGLED_NAME(name) "_" #name "@4"
-#endif
+#define JP_CA_MANGLED_NAME(name) #name
 
 #endif // #ifndef MsiCA_h
diff --git a/src/jdk.jpackage/windows/native/msiwrapper/MsiWrapper.cpp b/src/jdk.jpackage/windows/native/msiwrapper/MsiWrapper.cpp
index 405a4cbf0a9..df09aae8079 100644
--- a/src/jdk.jpackage/windows/native/msiwrapper/MsiWrapper.cpp
+++ b/src/jdk.jpackage/windows/native/msiwrapper/MsiWrapper.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2019, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -83,7 +83,7 @@ void launchApp() {
 } // namespace
 
 
-int __stdcall WinMain(HINSTANCE, HINSTANCE, LPSTR lpCmdLine, int nShowCmd) {
+int WinMain(HINSTANCE, HINSTANCE, LPSTR lpCmdLine, int nShowCmd) {
     app::wlaunch(std::nothrow, launchApp);
     return exitCode;
 }
diff --git a/test/hotspot/jtreg/runtime/jni/nativeStack/libnativeStack.c b/test/hotspot/jtreg/runtime/jni/nativeStack/libnativeStack.c
index 2b75f29aa83..1087ff2ca89 100644
--- a/test/hotspot/jtreg/runtime/jni/nativeStack/libnativeStack.c
+++ b/test/hotspot/jtreg/runtime/jni/nativeStack/libnativeStack.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2022, 2024, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -72,7 +72,7 @@ void generateError(JNIEnv *env) {
 }
 
 #ifdef _WIN32
-unsigned __stdcall
+unsigned
 #else
 void *
 #endif
diff --git a/test/hotspot/jtreg/vmTestbase/nsk/share/native/native_thread.cpp b/test/hotspot/jtreg/vmTestbase/nsk/share/native/native_thread.cpp
index 4e8bf729cff..089aab78bb5 100644
--- a/test/hotspot/jtreg/vmTestbase/nsk/share/native/native_thread.cpp
+++ b/test/hotspot/jtreg/vmTestbase/nsk/share/native/native_thread.cpp
@@ -90,7 +90,7 @@ void* THREAD_new(PROCEDURE procedure, void* context) {
 /***************************************************************/
 
 #ifdef windows
-unsigned __stdcall procedure(void* t) {
+unsigned procedure(void* t) {
 #else // !windows
 void* procedure(void* t) {
 #endif