Windows Defender/Windows Security failed to launch.
Windows Defender/Windows Security failed to launch.
I attempted to review group policies and the registry editor, fix the system image, and recover damaged files. No third-party antivirus was used. I'm unsure how long this has been happening since I only noticed it recently. Other users on the machine are also experiencing issues. They report that the application won't launch, even with right-click scanning. At this stage, they're considering a full reformat and reinstallation of Windows. Any alternative solutions have you tried? Edit: From the service view, Defender appears active but fails to start when opened. It seems the firewall is likely the root cause.