How to Remove a Windows File Protection Error

1. Start your computer in Safe Mode. Do this by hitting the F8 key repeatedly as you turn it on.
2. Run an antivirus program. Windows comes with a tool known as the Malicious Software Removal Tool, which you can find by going to Start -> Run and typing 'MRT.' Third-party antivirus software like Norton or McAfee will work as well.
3. Restart your computer normally. Go to the Run dialogue in the Start menu. Type 'regsvr32 initpki.dll' (no quotes) and hit 'OK.' This will reset the registry file(s) affected by the bug. Restart your computer again.