Cheat Engine

[ArcaneKnite]

It says something about a USB device malfunctioning (impossible because I have none attached), my CD/DVD drive malfunctioning (it still works, I tested it) or my harddrive screwing up (most probably here).

Would reformatting help the problem, or is it most likely a hardware problem and not a virus when this happens?

And if it is a virus, is there a way to get it to start up normally without reformatting first, because I have files I need to back up.

[AhMunRa]

Rather that reinstall, try an inplace repair. Load your Windows disk, go through the setup menu, and when you select where to install should give you the option to repair the install, note this is not the same as repair console.