My friend ask me to help him figure out whats wrong with his Dell XPS 410 with Vista home premium installed. The box is about 7 years old. It will reboot when left alone for a period of time. He says it made a squealing noise just before it started this. I sat it up on my bench with the side off and watched the fans during boot, they all came on OK, but the CPU fan might be running slow. There doesn't seem to be a lot of heat around the CPU(haven't check the temp with Everest, or any other utility yet) Also, while running the computer under load there's no lock ups or slow running or anything to indicate a heat problem. It will run fine till you let it set for a while them it will reboot and stop at the log in screen. I've tried resetting the RAM(2 sticks-2gb)didn't seem to make a difference. I think I'll take the heat sink & fan assembly off tomorrow and clean them(after I backup his data and pics)see that that helps. Would anyone have any ideas on this problem? Thanks in advance.