--- a/testing/mozharness/configs/unittests/win_taskcluster_unittest.py
+++ b/testing/mozharness/configs/unittests/win_taskcluster_unittest.py
@@ -255,17 +255,27 @@ config = {
                     'mozharness', 'external_tools', 'mouse_and_screen_resolution.py'),
                 '--configuration-file',
                 os.path.join(os.getcwd(),
                     'mozharness', 'external_tools', 'machine-configuration.json')
             ],
             'architectures': ['32bit', '64bit'],
             'halt_on_failure': True,
             'enabled': ADJUST_MOUSE_AND_SCREEN
-        }
+        },
+        {
+            'name': 'hide win 10 taskbar',
+            'cmd': [
+                'powershell', '-command',
+                '"&{$p=\'HKCU:SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\StuckRects3\';$v=(Get-ItemProperty -Path $p).Settings;$v[8]=3;&Set-ItemProperty -Path $p -Name Settings -Value $v;&Stop-Process -ProcessName explorer}"'
+            ],
+            'architectures': ['32bit', '64bit'],
+            'halt_on_failure': True,
+            'enabled': os.environ.get('ProgramFiles(x86)', False)
+        },
     ],
     "vcs_output_timeout": 1000,
     "minidump_save_path": "%(abs_work_dir)s/../minidumps",
     "buildbot_max_log_size": 52428800,
     "default_blob_upload_servers": [
         "https://blobupload.elasticbeanstalk.com",
     ],
     "structured_suites": ["reftest"],