...although I am not a gamer I have recently been through the XP/Nvidia grinder...here is what I have learned:
the (Gateway) driver update offered by MS is severely limited; the 23.11 drivers from Nvidia (unsigned) were slightly half-baked; the 27.50 drivers (unsigned) from Visiontek work very well; but, it is necessary to use Powerstrip (the shareware) to crank XP out of its ironclad 60Hz refresh default.
I am presently running a Hitachi CM828/GeForce3 combination at 2048 x 1536 (16 bit color) with Coolbits to overclock the card to 220/520 and Powerstrip to set the correct refresh to 71 Hz...and all is well...Autocad and Sach's Aquarium seem to like this combo better than any other...and I don't miss the 32 bit color...
Good luck...a little patience and tinkering pays off
P4 1.7
512MB rambus
ABIT MBoard
AGP aperture @ 128