Okay, virus might directly affect your PC's temperature. However, I'd clean it up from the inside anyway as it is one of the most common causes of overheating (bad ventilation because dust cloggs airholes).
Second, you can open task manager, check the process that's affecting your PC, find it's location, restart in safe mode and delete it, but that's still not as convenient as windows reinstall.
Sorry, but if you damaged your windows so bad (jumping errors out of the blue, overheating etc.) your best solution would be clean install, like Triad said.
Once your system files get damaged and corrupted, (even though you can try to use sfc/scannow in command prompt) your PC will never act as fast as before until you reinstall it.