400SD4 display problem

I'm getting the following error message, then my display on my laptop goes
to 2 colors and don't remember the resolution, but very large. After
rebooting, everything is back to normal. I have used the Gatgeway update
tool to update drivers, and still the same thing.

The ati2dvag display driver has stopped working normally. Save your work
and reboot the system to restore full functionality. Tye next time you
reboot the machine a dialog will be displayed giving you a chance to upload
data to Microsoft.

I've also made sure all my microsoft software and drivers are current from
the Windows update. Anyone have any idea what is going on and what I can do
to fix this?

Thanks,
Michael