Sound Card causing poor performance?

After trying forever to find why I'm getting such poor performance in games like bf2 and 2142, crysis, far cry and others, I thought of one thing I may have over looked before. I get like 58- 28 fps in those games, especially when a lot is going on. I thought a 8800gt would solve that. Could my sound card potientially be causing loss in fps? I have no idea what model it is, but its a Xfi Sound Blaster, so I dont know which one to download drivers for.

Here's my system: 8800GT 4gig ram, Windows xp, 10,000 rpm hdd, e6600 @ 2.4 ghz and 750 watt psu

Thanks!