diff --git a/Lib/test/_test_embed_set_config.py b/Lib/test/_test_embed_set_config.py
index 0c016b5d75d734..a2ddd133cf47c8 100644
--- a/Lib/test/_test_embed_set_config.py
+++ b/Lib/test/_test_embed_set_config.py
@@ -9,9 +9,9 @@
 import os
 import sys
 import unittest
+from test.support import MS_WINDOWS
 
 
-MS_WINDOWS = (os.name == 'nt')
 MAX_HASH_SEED = 4294967295
 
 class SetConfigTests(unittest.TestCase):
diff --git a/Lib/test/pythoninfo.py b/Lib/test/pythoninfo.py
index 1ec04de3c0c94f..c0b21124499df0 100644
--- a/Lib/test/pythoninfo.py
+++ b/Lib/test/pythoninfo.py
@@ -704,6 +704,19 @@ def collect_test_support(info_add):
     attributes = ('IPV6_ENABLED',)
     copy_attributes(info_add, support, 'test_support.%s', attributes)
 
+    attributes = (
+        'MS_WINDOWS',
+        'has_fork_support',
+        'has_socket_support',
+        'has_strftime_extensions',
+        'has_subprocess_support',
+        'is_android',
+        'is_emscripten',
+        'is_jython',
+        'is_wasi',
+    )
+    copy_attributes(info_add, support, 'support.%s', attributes)
+
     call_func(info_add, 'test_support._is_gui_available', support, '_is_gui_available')
     call_func(info_add, 'test_support.python_is_optimized', support, 'python_is_optimized')
 
diff --git a/Lib/test/support/__init__.py b/Lib/test/support/__init__.py
index fb69d9f7af018d..22495748ddb097 100644
--- a/Lib/test/support/__init__.py
+++ b/Lib/test/support/__init__.py
@@ -46,7 +46,7 @@
     "check_disallow_instantiation", "check_sanitizer", "skip_if_sanitizer",
     "requires_limited_api", "requires_specialization",
     # sys
-    "is_jython", "is_android", "is_emscripten", "is_wasi",
+    "MS_WINDOWS", "is_jython", "is_android", "is_emscripten", "is_wasi",
     "check_impl_detail", "unix_shell", "setswitchinterval",
     # os
     "get_pagesize",
@@ -509,6 +509,8 @@ def requires_legacy_unicode_capi():
     return unittest.skipUnless(unicode_legacy_string,
                                'requires legacy Unicode C API')
 
+MS_WINDOWS = (sys.platform == 'win32')
+
 # Is not actually used in tests, but is kept for compatibility.
 is_jython = sys.platform.startswith('java')
 
diff --git a/Lib/test/test_asyncio/test_subprocess.py b/Lib/test/test_asyncio/test_subprocess.py
index dc5a48d500e8d5..179c8cb8cc17cf 100644
--- a/Lib/test/test_asyncio/test_subprocess.py
+++ b/Lib/test/test_asyncio/test_subprocess.py
@@ -14,8 +14,7 @@
 from test.support import os_helper
 
 
-MS_WINDOWS = (sys.platform == 'win32')
-if MS_WINDOWS:
+if support.MS_WINDOWS:
     import msvcrt
 else:
     from asyncio import unix_events
@@ -283,7 +282,7 @@ def test_stdin_broken_pipe(self):
         rfd, wfd = os.pipe()
         self.addCleanup(os.close, rfd)
         self.addCleanup(os.close, wfd)
-        if MS_WINDOWS:
+        if support.MS_WINDOWS:
             handle = msvcrt.get_osfhandle(rfd)
             os.set_handle_inheritable(handle, True)
             code = textwrap.dedent(f'''
diff --git a/Lib/test/test_cppext/__init__.py b/Lib/test/test_cppext/__init__.py
index a322f417a774f0..f02a823bd22176 100644
--- a/Lib/test/test_cppext/__init__.py
+++ b/Lib/test/test_cppext/__init__.py
@@ -10,7 +10,6 @@
 from test.support import os_helper
 
 
-MS_WINDOWS = (sys.platform == 'win32')
 SOURCE = os.path.join(os.path.dirname(__file__), 'extension.cpp')
 SETUP = os.path.join(os.path.dirname(__file__), 'setup.py')
 
@@ -27,7 +26,7 @@ def test_build_cpp03(self):
 
     # With MSVC, the linker fails with: cannot open file 'python311.lib'
     # https://github.com/python/cpython/pull/32175#issuecomment-1111175897
-    @unittest.skipIf(MS_WINDOWS, 'test fails on Windows')
+    @unittest.skipIf(support.MS_WINDOWS, 'test fails on Windows')
     # Building and running an extension in clang sanitizing mode is not
     # straightforward
     @unittest.skipIf(
diff --git a/Lib/test/test_cppext/setup.py b/Lib/test/test_cppext/setup.py
index 976633bc33889c..c7ba1efb4dd05a 100644
--- a/Lib/test/test_cppext/setup.py
+++ b/Lib/test/test_cppext/setup.py
@@ -4,15 +4,13 @@
 import shlex
 import sys
 import sysconfig
+from test import support
 
 from setuptools import setup, Extension
 
 
-MS_WINDOWS = (sys.platform == 'win32')
-
-
 SOURCE = 'extension.cpp'
-if not MS_WINDOWS:
+if not support.MS_WINDOWS:
     # C++ compiler flags for GCC and clang
     CPPFLAGS = [
         # gh-91321: The purpose of _testcppext extension is to check that building
diff --git a/Lib/test/test_embed.py b/Lib/test/test_embed.py
index 582392ecddcb91..24617ab24c6958 100644
--- a/Lib/test/test_embed.py
+++ b/Lib/test/test_embed.py
@@ -1,8 +1,6 @@
 # Run the tests in Programs/_testembed.c (tests for the CPython embedding APIs)
 from test import support
-from test.support import import_helper
-from test.support import os_helper
-from test.support import requires_specialization
+from test.support import import_helper, os_helper, MS_WINDOWS
 import unittest
 
 from collections import namedtuple
@@ -21,7 +19,6 @@
 if not support.has_subprocess_support:
     raise unittest.SkipTest("test module requires subprocess")
 
-MS_WINDOWS = (os.name == 'nt')
 MACOS = (sys.platform == 'darwin')
 PYMEM_ALLOCATOR_NOT_SET = 0
 PYMEM_ALLOCATOR_DEBUG = 2
@@ -347,7 +344,7 @@ def test_simple_initialization_api(self):
         out, err = self.run_embedded_interpreter("test_repeated_simple_init")
         self.assertEqual(out, 'Finalized\n' * INIT_LOOPS)
 
-    @requires_specialization
+    @support.requires_specialization
     def test_specialized_static_code_gets_unspecialized_at_Py_FINALIZE(self):
         # https://github.com/python/cpython/issues/92031
 
diff --git a/Lib/test/test_faulthandler.py b/Lib/test/test_faulthandler.py
index cfc7ce5a86bab8..67ebc554cddb7c 100644
--- a/Lib/test/test_faulthandler.py
+++ b/Lib/test/test_faulthandler.py
@@ -7,8 +7,7 @@
 import subprocess
 import sys
 from test import support
-from test.support import os_helper
-from test.support import script_helper, is_android
+from test.support import os_helper, script_helper, is_android, MS_WINDOWS
 from test.support import skip_if_sanitizer
 import tempfile
 import unittest
@@ -23,7 +22,6 @@
     raise unittest.SkipTest("test module requires subprocess")
 
 TIMEOUT = 0.5
-MS_WINDOWS = (os.name == 'nt')
 
 
 def expected_traceback(lineno1, lineno2, header, min_count=1):
diff --git a/Lib/test/test_gdb/__init__.py b/Lib/test/test_gdb/__init__.py
index d74075e456792d..99557739af6748 100644
--- a/Lib/test/test_gdb/__init__.py
+++ b/Lib/test/test_gdb/__init__.py
@@ -9,8 +9,7 @@
 from test import support
 
 
-MS_WINDOWS = (os.name == 'nt')
-if MS_WINDOWS:
+if support.MS_WINDOWS:
     # On Windows, Python is usually built by MSVC. Passing /p:DebugSymbols=true
     # option to MSBuild produces PDB debug symbols, but gdb doesn't support PDB
     # debug symbol files.
diff --git a/Lib/test/test_utf8_mode.py b/Lib/test/test_utf8_mode.py
index ec29ba6d51b127..f66881044e16df 100644
--- a/Lib/test/test_utf8_mode.py
+++ b/Lib/test/test_utf8_mode.py
@@ -9,10 +9,9 @@
 import unittest
 from test import support
 from test.support.script_helper import assert_python_ok, assert_python_failure
-from test.support import os_helper
+from test.support import os_helper, MS_WINDOWS
 
 
-MS_WINDOWS = (sys.platform == 'win32')
 POSIX_LOCALES = ('C', 'POSIX')
 VXWORKS = (sys.platform == "vxworks")