AUTOMATIC REBOOT, WIN 2K OS

Did this just start or has it been happening since you've had the computer?
I have seen some network cards cause this problem. They detect the shutdown signals as a PXE wakeup message and cause the computer to restart. Go into you system BIOS and disable Wake on LAN or PXE Wake up Events. If that doesn't help, try removing the network card to see if it is the offending party. It could be another slotted card as well. try removing them one at a time. If the NIC is integrated, try disabling it in the BIOS. It could also be related to Power Management. Try disabling it in your BIOS as well.

If you use the Power Options tool in Control Panel to configure your computer power button for shutdown and an attempt to shutdown your computer is denied by application, your computer does no restart when you click Restart on the Start menu.

Windows 2000 does not reset the Power Policy action after an application denial to a power management request occurs, and because of this, the following restart request is treated as a shut down request.

RESOLUTION
A supported fix is now available from Microsoft, but it is only intended to correct the problem described in this article and should be applied only to systems experiencing this specific problem. This fix may receive additional testing at a later time, to further ensure product quality. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Windows 2000 service pack that contains this fix.

To resolve this problem immediately, contact Microsoft Product Support Servicesto obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, please go to the following address on the World Wide Web:

http://support.microsoft.com/directory/overview.asp