System restarting during boot
I noticed one of my servers was restarting itself erratically this morning. A quick look at the logs showed that it had been doing this all weekend - restarting after it had been up for an hour, 30 min, 10, etc. My first thought was the the PS was going bad, no big problem. After switching out the PS, the power cable, using different outlets, etc, I've concluded that the PS is probably not involved.
Then the system started rebooting DURING the boot sequence. I'd get into the GUI part of the boot, and the machine would power down and restart. I tried to do a system repair, using the CD and emergency repair disk. Then I started getting an "Unknown hard error" with reference to ntdll.dll. I replaced this file from another W2K machine with the same configuration to no avail. I've removed/replaced every component except the mb and chip, with no visible effect. Now the machine is rebooting during the text phase of boot, and I'm even more confused. The only change to the OS I've made recently is that I may have installed SP3 (the only real problems I've seen related to that so far, though, are drivers for add-on cards, and I don't have any). Any ideas on what's going on?