Can't change resolution from 680x480, maybe conflict with intel driver

So im trying to help my brother fix a problem hes having with his resolution settings. basically his video card died so while he was waiting for his replacement card (a GTX260), he installed the drivers for his integrated intel graphics (G31).

When he got his GTX260, he did not disable or uninstall the drivers of the intel integrated graphics, but just inserted the GTX260. Windows recognizes the the video card fine and he installed the latest NVIDIA drivers (260.99) but even with the drivers, his resolution is stuck at 680x480, it cannot be changed in windows resolution settings or in nvidia control panel.

this is when he asked me to help him, and upon googling ive found that many people experienced problems when they did not first disable or uninstall the drivers of the intel integrated graphics and just installed their dedicated video card, which is exactly what my brother did so im thinking that there is a driver conflict with the intel drivers.

I first tried uninstalling the intel graphics drivers through add/remove programs. same problem. i then tried cleaning out the intel drivers by running Driver Cleaner Pro in safe mode and selecting the intel extreme filter to clean it out. still same problem.

i then decided to start from square one and removed the gtx 260 (used the intel graphics again), cleaned out all drivers (both intel and nvidia) via add/remove programs and driver cleaner pro. then reinstall the gtx260 and install the latest nvidia drivers. again, still resolution is staying at 680x480 and its unable to change.

im at a lost at what to do except for a reformat of his HDD (for a fresh driver installation) but my brother doesnt want to do that as he has a lot of files and no backups.

also it should be noted that he can play games with the GTX260 fine, he only ran CSS and Killing Floor (UT04 engine) but it runs smoothly and most importantly, the resolutions can be changed ingame without any trouble. its only at the desktop that the resolution is stuck at 680x480.

His mobo is a GIGABYTE GA-G31M-S2L , he is running Windows XP 32bit and his monitor is a Samsung 932BW 19' widescreen (native res 1440x990)