Fix Windows Defender 404 Not Found Error on Windows 10
You click to open Windows Defender Security Center and see a 404 page, or the Settings app shows ...
Checklists for software errors, setup, and tool workflows.
1. Reproduce
2. Isolate
3. Apply
4. Verify
Latest checklists
View listFix Microsoft Store Apps Not Downloading or Stuck
You open Microsoft Store, tap download, and nothing happens—or the progress bar barely moves. Thi...
WireGuard Handshake Not Completing: Practical Fixes
After setting up WireGuard, you might see the peer listed but the handshake never completes. This...
Fix Chrome File Locked by Background Process Error
You try to delete or move a file, and Windows tells you it's locked by a Chrome background proces...
How to Repair Outlook PST File When It Fails to Start
If Outlook fails to start and you see errors like 'Cannot start Microsoft Outlook' or 'The file p...
Fix Remote Desktop Error 0x104: Connection Failed
When you see "Remote Desktop failed to connect with error code 0x104", the connection attempt was...
Topic paths
Quick titles
Fix Microsoft Teams Blank Screen on StartupResolve Windows Security Invalid Configuration ErrorWindows Update Fails Due to Port 80 in UseFix File History Backup Not Working on Windows 10Task Scheduler SSL Error Setup Guide: Fix Common Certificate IssuesHow to Fix Remote Desktop Error 0x4 Caused by CacheChecklist to Fix Windows Update Port Allocation ErrorMicrosoft Store Connection Refused: Proxy Troubleshooting Guide