Try to boot the system in VGA mode...
The following is from MS Technet article. I did not write this:
"VGA Mode
If Windows NT does not start or if distorted or unreadable text appears on the screen, start your computer using VGA mode. By default, the Windows NT boot loader menu offers options to start normally or in VGA mode. To force Windows NT to use the standard VGA driver, choose the VGA Mode option.
If VGA mode works correctly, please see the "The Ability to Easily Change Display Settings" section in this article. If VGA mode is unsuccessful, please see the "Last Known Good Configuration" section in this article."
Joseph L. Poandl
MCSE 2000