Fix Windows Defender Service Not Starting (Error 404)
If you see error 404 when trying to start Windows Defender, it usually means the service executab...
Checklists for software errors, setup, and tool workflows.
1. Reproduce
2. Isolate
3. Apply
4. Verify
Latest checklists
View listFix Windows Activation File Locked in Safe Mode
Users sometimes find that after booting into Safe Mode to troubleshoot a system issue, Windows ac...
How to Fix Windows Defender Blocked by Group Policy
When you try to open Windows Defender and see a message like "This app is blocked by group policy...
Troubleshoot 504 Gateway Timeout in Windows Security App
When you open Windows Security (formerly Windows Defender Security Center) and see a 504 ...
Fix Chrome Profile Port Already Allocated Error
You try to launch Chrome with a specific profile using the --user-data-dir and
Fix Chrome ERR_CONNECTION_RESET After Update
If you're seeing "ERR_CONNECTION_RESET" in Chrome right after an update, you're not alone. This e...
Topic paths
Quick titles
How to Fix Microsoft Teams Token Expired Error Without ReinstallingFix Remote Desktop Permission Denied Without Admin RightsReal-Time Protection Greyed Out – Quick FixesFix OpenVPN Connection Failed with Exit Code 1How to Break an Outlook Login LoopHow to Stop Teams Authentication Loop After UpdateTask Scheduler Backup Failure Troubleshooting GuideWindows 11: How to Run PowerShell Scripts