I have had a weird problem with my computer for at least a couple of years. When I shut down my computer, and then turn it back on, the cooling fan starts spinning at a very high speed and it will not boot up. The fan remains spinning, and would probably continue to spin for hours. If I turn the PC off again and then wait for an hour, it will finally boot up, but the fan is still spinning at high-speed. It remains spinning even after booting into Windows. I have to shut it down again and then wait another hour. Finally, the next time I turn it back on, it boots up and the fan behaves normally. I did a Google search to see if I can find a fix. On another forum someone had a similar issue, and one post suggested resetting the CMOS battery. Does this sound like something that would be caused by a problem with the CMOS battery? I was also wondering if it might be a problem with the power supply.