Windows Defender Service Troubleshooting Checklist
If Windows Defender won't start, won't update, or shows error messages like "Service stopped" or ...
Checklists for software errors, setup, and tool workflows.
1. Reproduce
2. Isolate
3. Apply
4. Verify
Latest checklists
View listWindows Defender High CPU and Memory Usage Not Working: Fixes
If Windows Defender is eating up CPU or memory and also failing to run scans, update definitions,...
Fix Windows Search Permission Denied in Windows 11
You type a query into the Start menu or File Explorer search box, but instead of results, you get...
How to Fix PowerShell Access Denied Errors on Windows
When you run a PowerShell command or script and see an 'Access Denied' error, it usually means Po...
Fix Windows Defender Token Expired Error After Reinstall
After reinstalling Windows or your security software, you might see a “token expired” error in Wi...
How to Fix Windows Defender Not Starting Automatically
If Windows Defender (Microsoft Defender Antivirus) isn't starting automatically when you boot you...
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