Fix 'Security Module Not Found' in Windows Defender
If you see a message in Windows Security that says something like "Security module not found" or ...
Checklists for software errors, setup, and tool workflows.
1. Reproduce
2. Isolate
3. Apply
4. Verify
Latest checklists
View listCloudflare Tunnel Health Check Troubleshooting Guide
When a Cloudflare Tunnel (formerly Argo Tunnel) health check fails, your origin server may be mar...
Fix Windows Defender Login Loop After Update
After a Windows update, some users find themselves stuck in a login loop when opening Windows Def...
Fix Windows Activation Error Invalid Configuration
You try to activate Windows and see an error saying “invalid configuration”. Thi...
How to Fix Windows Security High CPU Usage
If your PC feels sluggish and Task Manager shows Windows Security (or Antimalware Service Executa...
Fixing 'Remote Desktop SSL Certificate Not Trusted' Error
When you try to connect to a remote computer using Remote Desktop (RDP) and see a warning that th...
Topic paths
Quick titles
Troubleshoot Windows Search Blank Screen by Restoring DefaultsHow to Resolve Teams Backup Permission DeniedTroubleshoot Microsoft Store Loading Screen IssueHow to Resolve Outlook Authentication FailedBitLocker Recovery Key Not Syncing Between PCsFix BitLocker Drive Access Denied in Windows 10CMD Authentication Failed Error Windows 10 TroubleshootingOneDrive Stuck on Processing Changes: How to Fix