Windows Defender 502 Bad Gateway: Troubleshooting Checklist
If you see a 502 Bad Gateway error when opening Windows Security or trying to update Windows Defe...
Checklists for software errors, setup, and tool workflows.
1. Reproduce
2. Isolate
3. Apply
4. Verify
Latest checklists
View listHow to Fix Windows Update Error 0x80070002
Windows Update error 0x80070002 usually means the update files are missing or corrupted. It often...
How to Fix Command Prompt Failed to Start on Windows 10
If you click on Command Prompt and nothing happens, or you see an error like “Windows cannot find...
Fix Windows Activation Error: DNS Name Does Not Exist
When you try to activate Windows and see an error that the DNS name does not exist, it usually me...
Fix Chrome Profile Invalid Configuration Permission Denied
If you see 'invalid configuration' or 'permission denied' when opening Chrome, your user profile ...
Enable File History Backup on Windows 10: Troubleshooting Guide
You set up File History on Windows 10, but backups aren't running, or the drive isn't detected. T...
Topic paths
Quick titles
Resolve Windows Security Startup Error Due to Group PolicyFix Task Scheduler Logon as Batch Job Permission DeniedTroubleshoot Outlook for Mac CrashesWindows Activation Module Not Found – How to FixFix Windows Terminal Authentication Failure After UpdateWindows Update Authentication Failed Domain User FixWindows Security Disabled by Group Policy – Quick Fix GuideTroubleshooting Windows Update Version Conflict