diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index 97d2190..6b8acb2 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -59,10 +59,14 @@
         support.reap_children()
 
     def tearDown(self):
-        for inst in subprocess._active:
-            inst.wait()
-        subprocess._cleanup()
-        self.assertFalse(subprocess._active, "subprocess._active not empty")
+        if not mswindows:
+            # subprocess._active is not used on Windows and is set to None.
+            for inst in subprocess._active:
+                inst.wait()
+            subprocess._cleanup()
+            self.assertFalse(
+                subprocess._active, "subprocess._active not empty"
+            )
         self.doCleanups()
         support.reap_children()
 
@@ -2679,8 +2683,12 @@
         with support.check_warnings(('', ResourceWarning)):
             p = None
 
-        # check that p is in the active processes list
-        self.assertIn(ident, [id(o) for o in subprocess._active])
+        if mswindows:
+            # subprocess._active is not used on Windows and is set to None.
+            self.assertIsNone(subprocess._active)
+        else:
+            # check that p is in the active processes list
+            self.assertIn(ident, [id(o) for o in subprocess._active])
 
     def test_leak_fast_process_del_killed(self):
         # Issue #12650: on Unix, if Popen.__del__() was called before the
@@ -2701,8 +2709,12 @@
             p = None
 
         os.kill(pid, signal.SIGKILL)
-        # check that p is in the active processes list
-        self.assertIn(ident, [id(o) for o in subprocess._active])
+        if mswindows:
+            # subprocess._active is not used on Windows and is set to None.
+            self.assertIsNone(subprocess._active)
+        else:
+            # check that p is in the active processes list
+            self.assertIn(ident, [id(o) for o in subprocess._active])
 
         # let some time for the process to exit, and create a new Popen: this
         # should trigger the wait() of p
@@ -2714,7 +2726,11 @@
                 pass
         # p should have been wait()ed on, and removed from the _active list
         self.assertRaises(OSError, os.waitpid, pid, 0)
-        self.assertNotIn(ident, [id(o) for o in subprocess._active])
+        if mswindows:
+            # subprocess._active is not used on Windows and is set to None.
+            self.assertIsNone(subprocess._active)
+        else:
+            self.assertNotIn(ident, [id(o) for o in subprocess._active])
 
     def test_close_fds_after_preexec(self):
         fd_status = support.findfile("fd_status.py", subdir="subprocessdata")