Boot to the DOS prompt. Change to the Windows Directory.
type:
win /?
You can add switches to control the start. Selecting BOOTLOG or something like that (I haven't got 3.1 on system right now). That selection will create a BOOTLOG.TXT file. i think this will be in C:\. Look at this file to see how far the boot got before it crashed. You may be able to remove a bad command if that is causing the problem.
Dennis