HELP! XP local user screen goes blank

Hello, we have a new Dell Laptop.

Set up so that dual monitors, worked fine on friday but now when my boss logs in the laptop screen starts up as normal gets to the descktop blinks then goes black. I have talked with Dell, I have gone into the display and made sure that both monitors were working. Log out log back in as her same thing happens, If i log on as administrator it works lovely, even when the second monitor not attached the laptop will do the same thing. We never set her up with adminstrator rights as we didn’t want her fooling around with anything or downloading programs to screw it up. So can’t even restore her last good logon. Any thoughts other than creating a new user.
PLEASE!