Windows Defender Service Troubleshooting Checklist
If Windows Defender won't start, won't update, or shows error messages like "Service stopped" or ...
Checklists for software errors, setup, and tool workflows.
1. Reproduce
2. Isolate
3. Apply
4. Verify
Latest checklists
View listFix Outlook Calendar Sync Issues on iPhone
If your Outlook calendar events aren't showing up on your iPhone, or changes you make on one devi...
Fix Chrome Login Loop: Steps to Break the Cycle
You enter your credentials on a site, Chrome reloads, and you're back at the login screen. This l...
Fix Task Scheduler 'File Locked' or 'Access Denied' Errors
You set up a scheduled task to run a script or program, but it fails with 'File Locked' or 'Acces...
Fix BitLocker Permission Denied Access to Drive
You try to open a BitLocker-encrypted drive and get an 'access denied' or 'permission denied' err...
Checklist for Fixing OneDrive SSL Certificate Issues
You see an error like "A certificate chain could not be built" or "SSL certificate problem" when ...
Topic paths
Quick titles
How to Fix Microsoft Store Not Opening After UpdateWindows Terminal Connection Refused: Troubleshooting ChecklistFix Microsoft Store Connection Refused ErrorHow to Fix Blank PowerShell Screen on ResizeHow to Fix Edge Update Error 0x80070643Command Prompt Update Problems: Troubleshooting StepsHow to Deploy Chrome Profiles via DownloadResolve Teams Path Missing in Registry