i also have problem with my windows 2000 lately. it just keep auto restart when reached network logon (password key in page). all other mode will auto restart when reached network logon password key in page, with no warning. when i used safe mode, i can go in windows 2000, but can't do any changes on "display properties" or use registry medic to "scan registry".. etc.. must be very careful, it can just restart just like if do anything not carefully. when i check event viewer while in safemode, i saw this service fail that service never run... bla bla bla. i can't start those services manually somemore (it give out..something like " never start for long time" or somesort of crap bill gate error msg). i don't have the error msg here. next time i provide. i scanned with antivirus, no virus. mostly it is driver or some of the stupid "registry firewall" caused problem. because the day before i installed registry firewall, but the software hang.. hence i remove it. i also tried to install over the existing windows.. but even if i run with windows 2000 cd, it restarted also after sometime of loading driver.. thus, i don't know why. Because when using windows 2000 cd, the driver that it load is from the windows 2000 cd right ? so it is not using my hdd driver. (i think) i am no computer expert. can any body help ?

You can try hitting F8 on bootup and selecting "Last known good configuration". If that doesn't work, I'd run a repair on the operating system and see if that doesn't fix the problem. If it doesn't, backup any important data on the HDD (ie: remove the HDD and slave it into another 2000 PC and back the info up there) then reinstall your OS.