Fix Windows Defender Error 0x80070422: Won't Turn On - Fix Windows Search 404 Not Found Error-How to Troubleshoot Defender Update Failures

Updated 2026-06-13 16:34:38office-tools
Fix Windows Defender Error 0x80070422: Won't Turn On - Fix Windows Search 404 Not Found Error-How to Troubleshoot Defender Update Failures
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.