Fix 'Command Prompt Not Found' Error After Windows Update
After a Windows update, you might see a '404 not found' error when trying to open Command Prompt,...
Checklists for software errors, setup, and tool workflows.
1. Reproduce
2. Isolate
3. Apply
4. Verify
Latest checklists
View listFixing Windows Security Proxy Configuration Issues
When Windows Security (formerly Windows Defender Security Center) can't update virus definitions ...
Fix Task Scheduler Error 0x80070005 (Access Denied)
When a scheduled task fails with error 0x80070005 and the message "Access Denied", i...
Windows Defender Not Opening on Windows 11: How to Fix
If you click the Windows Defender icon or search for it and nothing happens, you're not alone. Th...
How to Fix Windows License Transfer to New Computer Issues
If you're trying to move your Windows license to a new computer and running into activation error...
Fix Windows Defender Token Expired Error in Command Prompt
When you run Windows Defender commands in Command Prompt as an administrator, you might see an er...
Topic paths
Quick titles
Fix Outlook Not Opening on Startup After UpdateFix Windows Security Offline Installer Error 0x80070643Step-by-Step PST Repair for Outlook Not OpeningResolve 'Windows Defender Firewall Has Blocked' NotificationTroubleshooting Chrome Dependency IssuesWindows Security Broken in Ubuntu Dual-Boot: FixHow to Fix Chrome Proxy Error on Windows 10How to Fix Microsoft 365 Sync in Windows Defender