My friend built this computer and then he gave it to me when he went to college. It is running vista home premium. All was fine and dandy until about two months ago where it started turning off and then restarting. I didn't really think about it to much until a month ago where it started going really really slow. I looked around in the processes and saw that it would ping to 100% cpu. It does this when I am not even running anything big. It also refuses to stream any videos, and frequently likes to freeze up on me. What should I do?