I have an older desktop that we upgraded recently. It was my parents and they put a bigger hard drive in it for us. Running Windows XP, 1gig ram, 250gig hard drive. It will work just great for a while, but if you do anything that really pushes it, like streaming video, or running several programs at once, it will just restart itself. I checked the fan first, it seems to be working. It worked just fine for like 3-4 months, then started having this issue. We used to have 2 ram chips in it, the 1gig and a 256 chip. We pulled the 256 thinking it may have a bad spot in it, and it seemed to work well again for like a week, then started up again. Any ideas?