Hi,
Please temporarily uninstall Security Essentials and check whether everything is working fine. If the issue is resolved, please reinstall Security Essentials again.
However, if the issue persists, you can try the following steps for a test.
1. Perform a Clean Boot to check the result. If the issue disappears in the Clean Boot environment, we can use a 50/50 approach to quickly narrow down which entry is causing the issue.
2. Run antivirus program and perform a full scanning.
3. Create a new user profile and login the new profile to check the result.
Thanks,
Novak