Hello, I apologize if this topic has been brought up a gazillion times, but I'm just too tired to search for it on the forums. Here are my computer specs: MSI K7N2 Delta-L (nForce2) motherboard AMD Athlon XP 2600+ Samsung 2x512MB DDR400 PC3200 RAM PowerColor ATI Radeon 9600 PRO Enermax 350W PSU Cooling: 2 Thermaltake case fans (front and back for air flow) 1 Thermaltake SilentBoost for CPU cooling (with Arctic Silver 5) DVD player, DVD Writer Just 1 MAXTOR 80GB 7200RPM hard drive I think that's all of it. Really simple system. Anyway, my computer does not restart when it is in Windows XP Pro, but only when it is during games (randomly). Sometimes just when the game loads, sometimes 15, sometimes 30 minutes into the game, sometimes 2 hours, sometimes never (Half-Life 2 and CSS seem to be the ones that rarely make my computer reboot). And I have no clue on what's going on. My CPU temperature when idle is 40-41 degrees Celcius. My system temperature is 36-37 degrees Celcius. I also ran memtest, and it showed absolutely no errors with the RAM. Edit: CAS settings at 3-3-3-8. Edit: FSB at 166 Mhz (2600+ running at 2.08 ghz) I have no idea what to do. I really don't want to format, because I doubt that is going to solve any problems whatsoever. And I know 350W PSU is more than enough with a simple system like this, especially when it only has one hard drive. Could it be the video card? I mean, if it was the video card, why would the games sometimes last longer? Half-Life 2 is a pretty demanding game, and it runs just fine. Same with Doom 3 by the way. But for example Flight Simulator 2004, Knights of the old Republic 2 and Age of Empires 3 demo recently don't want to run for a long time. Could it be that it's specific software that is causing this? I personally find no problem with my system whatsoever. Would formatting help in this case? Any help would be greatly appreciated, or any experiences with similar problems. Cheers.