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 MySQL 'Access Denied for User 'user'@'%'' Error
If you're seeing ERROR 1045 (28000): Access denied for user 'user'@'%', it means MyS...
Windows Activation Proxy Error: Complete Troubleshooting Checklist
When you see a Windows activation error that mentions a proxy, it usually means the activation cl...
Fix BitLocker Permission Denied Access to Drive
You try to open a BitLocker-encrypted drive and get an 'access denied' or 'permission denied' err...
Fix Windows Security Migration Not Working After Update
After a Windows update, you might find that Windows Security (formerly Windows Defender) fails to...
Fix Chrome 404 Error by Disabling Extensions
If you're seeing a 404 error in Chrome but the page loads fine in another browser, a misbehaving ...
Topic paths
Quick titles
How to Reset Corrupt Windows Search SettingsTroubleshoot Windows Activation Auto Launch FailureStop Chrome Draining Mac Battery: CPU FixesMissing mstsc.exe? Fix Remote Desktop ConnectionFix Windows Update Authentication Failed Due to Group PolicyTask Scheduler SSL Certificate Error: Troubleshooting GuideEnterprise Windows Defender TroubleshootingQuick Fix for Remote Desktop CredSSP NLA Failure