Windows 2000 Professional won’t startup!

I just installed windows 2K prof. on a brand new formated 40 gig harddrive. Everything was working fine and it was starting up fine until this afternoon. I have not changed anything and it won’t start up.

It gets stuck on the screen where it has the progress bar and says windows is starting. The progress bar moves a few bars and then gets stuck in the same place.

I was able to startup in safe mode but that took a long time.

Why would it start up one minute and not the next? Especially since I have not changed anything.

Could this be a virus problem or a device problem.

Can your bios get infected with a virus?

Anyhelp would be appreciated.