nvidia gforce 400mx

can any 1 help. Serious sam will not run on my system it says can not set display.
i have a athlon 1800+xp.
i have had the game running old my old nvidia graphics driver but it was'nt digitly signed so i updated the driver through windows xp and it put a mircosoft driver for the graphics card in.
Then serious sam would not run.
so i rollbacked the drivers to the old 1 and then my system started acting funny it would'nt open system comands like (restore,system hardware,)
evently got it to restore back and now works fine.
i have also download the new graphic drivers from nvidia and i get the same problem.
could this be any thing to do with the microsoft drivers as i am sure it was working fine before i put them on.
thanks.

Do you using old drivers for another Windows version?
You must have the XP drivers. Get them from nvidia.
MS drivers is just a software implementation that is used if you do not have the correct drivers installed. If you updated and still got problems can you try to reinstall them. Get rid of all drivers and use a VGA driver. Remove all driver software and then reinstall the XP drivers from nvidia.