I say, take off and nuke the entire site from orbit. It's the only way to be sure.
This is the reason Microsoft decided to develop their own anti-virus, because the companies who are supposed to develop them has a tendency to turn their software into unremovable malware with Catch 22 sales agents trying their best to prevent you from cancelling your subscriptions.
You're probably looking at manually deleting folders and registry keys to get your PC cleaned up. This guy's advice might work for you: