help me diamond viper 2 and counter strike

ok I just got a 900mhz athlon and 200 mhz motheboard and 256 pc133 ram and this card. It plays counterstrike poorly with tones of rendering lag. please help I heard that oplengl would be better cause my machine is fast but when i click on open gl in the 3d options in counter strike it tells me that my card does not support it!
please help

my old 333mhz 4mg graphics card played cs better than this does.