If your windows 2000 has forgotten where it has its drivers (it can't even locate its own standard drivers), one of your registry keys may be corrupted. (I don't really know why this happens, but I blame a buggy installer of some unknown program.)
If you have your Windows 2000 installed in c:\Winnt (and have a this folder: "C:\WINNT\inf"), you may run this reg-file to correct this problem. (It changes the key type to one which windows may expand).
You use this file at your own risk. But as far as I know, it should work.