I have a Win2k white box. It has been working with no problems for at least the last 4 months. Now, when I chose "shutdown" the system goes through normal routine, shuts down for about 4-5 seconds then powers up. I also tried holding the power button in for several seconds until it powers off. Again, after 4-5 seconds it powers on. I had to unplug the pc to power off. What is this? M/B, P/S, APM, etc...???