NT4 Need Help stopping Win Setup

I am trying to solve a problem caused by a former employee who tried to
install new printer and/or network drivers on to an NT4 system. When the
system powers up, it immediately restarts the Windows setup routine and does
not respond to user input (even ctrl-alt-del).
I've tried to delete (off-line) "RunOnce" registry values in
HKLM\software\microsoft\windows, but that did not help. Anyone know what
else to do?

Thanks