Yeah, I've checked fans for everything, reapplied heatsink for the processor, installed a higher wattage power supply, swapped every component inside the box for my PC back when I was using XP and it still rebooted. Even had some programs to monitor voltages and temps the whole time I was running. It's very random. I can run 2 world of warcraft clients at the same time for hours. Then later in the day, just go to use one and it'll reboot within a few minutes. Sometimes I go days without any reboots. I think it's an IRQ conflict but I only found the one way in XP to shift IRQ's and I haven't been able to do it in windows 7.