diff --git a/filetags/__init__.py b/filetags/__init__.py
index ceec5b9..ab79464 100755
--- a/filetags/__init__.py
+++ b/filetags/__init__.py
@@ -53,6 +53,9 @@ try:
 except ModuleNotFoundError:
     have_tkinter = False
 
+import stat
+import tempfile
+
 safe_import('operator')   # for sorting dicts
 safe_import('difflib')    # for good enough matching words
 safe_import('readline')   # for raw_input() reading from stdin
@@ -2521,6 +2524,7 @@ def assert_empty_tagfilter_directory(directory):
         if not options.dryrun:
             safe_import('shutil')  # for removing directories with shutil.rmtree()
             shutil.rmtree(directory)
+            force_rmtree(directory)
             logging.debug('re-creating tagfilter directory "%s" ...' % str(directory))
             os.makedirs(directory)
 
@@ -3278,6 +3282,29 @@ def main():
     successful_exit()
 
 
+def force_rmtree(path):
+    """Provide a rmtree compatible both for Linux/MacOS and Windows.
+
+    Previous definitions worked well for Linux/MacOS and their tests
+    by `unit_tests.py` launched by `pytest` passed with GitHub's
+    osrunners.  However, the very same tests constantly failed with
+    the osrunner of Windows.  After discussion, this function was
+    provided by Claude AI/Sonnet 4.6."""
+    import stat, tempfile
+    def _remove_readonly(func, fpath, _exc):
+        os.chmod(fpath, stat.S_IWRITE)
+        func(fpath)
+    # Windows locks the CWD; move away before attempting deletion
+    try:
+        cwd = os.getcwd()
+        if os.path.abspath(cwd).startswith(os.path.abspath(path)):
+            os.chdir(tempfile.gettempdir())
+    except Exception:
+        pass
+    if os.path.isdir(path):
+        rmtree(path, onerror=_remove_readonly)
+
+
 if __name__ == "__main__":
     try:
         main()
diff --git a/tests/unit_tests.py b/tests/unit_tests.py
index 99b210f..58c6ea2 100755
--- a/tests/unit_tests.py
+++ b/tests/unit_tests.py
@@ -417,8 +417,8 @@ class TestLocateAndParseControlledVocabulary(unittest.TestCase):
 
         # Note: cwd = subdir3
         # Let's create all missing files in all dirs:
-        filetags.create_link(self.subdir2_file, self.subdir1_file)  # create link
-        filetags.create_link(self.subdir2b_file, self.tempdir_file)  # create link
+        filetags.create_link(self.subdir2_file, self.subdir1_file + ".lnk")  # create link
+        filetags.create_link(self.subdir2b_file, self.tempdir_file + ".lnk")  # create link
 
         # prio 1 = .filetag file in startfile directory
         self.assertEqual(filetags.locate_and_parse_controlled_vocabulary(self.subdir1_test_file),