opengl problems in counterstrike

hello. i am having a huge problem. for a week ago I ran windows 98 and everything worked just fine, but then i upgraded to windows xp and i couldnt play counterstrike in opengl mode because it said my videocard couldn’t support that mode, but i have always played in that mode in windows 98. so i thought that this problem would fix if i just deleted windows xp and installed windows 98 again. but now i cant play in opengl in windows 98 either. i’ve the same drivers as always and even tried with glsetup from this webpage.

My videocard is a ASUS 6800 Deluxe which is a Geforce256.

you can look at the error picture here: