
Fix Windows Defender Access Denied Error on Startup
If you see 'Windows Defender failed to start access denied' when you open Windows Security or aft...
Software troubleshooting desk

If you see 'Windows Defender failed to start access denied' when you open Windows Security or aft...

You may see a message that your BitLocker token has expired, often after a BIOS update, hardware ...

If you see repeated credential prompts or Windows Security not saving settings, a cache sync issu...

You try to open a page in Chrome and see "Service Unavailable" or "This site can't be reached. Se...

If Windows Security (formerly Windows Defender) is running slowly on your Windows 11 PC—taking ag...

When your network connection acts up, the command prompt offers quick, built-in tools to pinpoint...