
Fix Windows Defender Connection Refused or Permission Denied Errors
If you see "connection refused" or "permission denied" when trying to start or update Windows Def...

If you see "connection refused" or "permission denied" when trying to start or update Windows Def...

You restart your PC to install updates, but instead of the usual progress screen, you get a blank...

If your OneDrive sync is stuck and you see a 404 Not Found error, it usually means the sync engin...

If you see an error saying your Outlook token has expired, it usually means the authentication to...

You click to open Windows Defender Security Center and see a 404 page, or the Settings app shows ...

If Windows Defender is disabled on your system—often due to group policy, third-party antivirus, ...