Looks like a lot of peeps have probs with g2
try the latest update 592 i think that sorted my g2 out
I think its mainly geforce 4 probs as Geforce 2 and geforce 3 both worked well in my pc when geforce wouldnt
Try the update i mentioned then
www.nvidia.com for latest geforce drivers,then
www.microsoft.com/directx for direct x9 drivers if all else fails.
Good luck an dont giv up