Fix 'Threat Service Stopped' in Windows 10 Defender - Windows 11 Defender Won't Open: Troubleshooting Guide-Troubleshoot BitLocker Recovery Key Not Accepted After BIOS Update

Updated 2026-06-13 12:13:19developer-tools
Fix 'Threat Service Stopped' in Windows 10 Defender - Windows 11 Defender Won't Open: Troubleshooting Guide-Troubleshoot BitLocker Recovery Key Not Accepted After BIOS Update
Before changing system settings, save your work and note the exact error text so you can compare results after each step.

Extra verification checklist

  • Restart the affected app after changing permissions or configuration files.
  • Test the same workflow in a clean browser profile or a temporary user account.
  • Compare the result on another network if the error may be connection related.