Fix 'Windows Security App Not Installed' on Windows 10
You open the Start menu, search for Windows Security, and nothing shows up. Or you see a message ...
Checklists for software errors, setup, and tool workflows.
1. Reproduce
2. Isolate
3. Apply
4. Verify
Latest checklists
View listHow to Fix a Blocked Windows Activation Product Key
You enter a Windows product key and see an error that the key is blocked or already in use. This ...
Windows Activation Service Unavailable on New Computer
You just set up a new computer, but when you try to activate Windows, you see an error that the a...
Fix OneDrive Sync Not Working After macOS Update
After a macOS update, OneDrive may stop syncing files or show error messages like “OneDrive is sy...
Windows Activation Authentication Failed: Troubleshoot Checklist
When Windows reports 'Activation authentication failed,' it usually means the system couldn't ver...
Fix Windows Activation Error: Permission Denied
You attempt to activate Windows and see an error message: “Permission denied” or “Access denied.”...
Topic paths
Quick titles
Check for Malware When Windows Activation Causes High CPU UsageResolve NO_PUBKEY error in UbuntuHow to Restore Edge Browser SettingsEnable Microsoft Defender via Local or Domain Group PolicyFix Microsoft Store App Stuck on Pending DownloadFirewall Blocking Windows Activation – Troubleshooting GuideWindows 10 Version Mismatch Error 0x8007232b FixHow to Fix Microsoft Store Timeout Caused by Firewall