Saw this post, tried the extra command, and it works !!!! -noforcemaccel is key. Use it, cstrike works sweet under xp for me now.
Enjoy -nick
A few forum-lovers and CS-Nation visitors sent in some quick fixes for problems with Half-Life/Counter-Strike and the new Windows XP.
First off, for those with SBLive! sound cards, add "+voice_dsound 1" to your Command/Target Line. Now, if you notice any mouse oddities, you're not alone! The mouse changes in XP are hard to get used to, so add "-noforcemparms -noforcemaccel" to your command line to use the standard mouse setup, which is much easier to handle.
Thanks, Opium (the person!).