Your pc is corrupt. It may just be one of the main files needed to run windows, but you need to do several things first. Check your start-up folder. You only need maybe one or two things in there depended on your needs. You can delete the rest. Having too many things running at once can cause memory loss and that will sometimes show up as a scrambled monitor.

If you have a good pc clean up program, then use it. I have Norton Systems work. Whatever one you have run it to check everything on your pC's hard drive. Those things are great and will find 99% of the problems and even fix them. (Like remove any spyware you might have collected unexpectedly)

You probably should defrag your hard drive also.