need help with a kg7-raid

need some help here guys..i am running windows xp pro, amd athlon 1.4, dual ibm 20gb(40gb total) raid 0, geforce 2 mx400. i play counterstrike often and it lags. i have no idea why. it started under windows 98se, ran a virus scan and quarantined the viruses. i then deleted them and my counterstrike started to mess up. i then reformatted my drives and installed xp, and it still skips when playing online. i have run virus scan about 30 times. right now all i have installed is counterstrike and a few other small proggies. nothing major. i have tried two video cards, a 32mb g2 gts and the mx 400. have no clue whats wrong. have the newest raid drivers and everything. maybe the viruses? please help.