
Windows Defender Service Troubleshooting Checklist
If Windows Defender won't start, won't update, or shows error messages like "Service stopped" or ...

If Windows Defender won't start, won't update, or shows error messages like "Service stopped" or ...

You see a message that a Windows update is pending install, but it fails with error 0x800f0922. T...

If your computer feels sluggish and you notice high memory usage in Task Manager, Windows Search ...

If you see an error like "File locked by system" when running a Windows Defender scan or trying t...

You open the Microsoft Store and instead of apps, you see a 504 error. This usually means the sto...

You boot into Safe Mode to repair a Windows issue, but BitLocker prompts for the recovery key and...