Wish I knew a solution....but heres the things I have read or done myself:
Update soundcard drivers
Update vidcard drivers
Update mobo drivers
Then I read it could be the server you're playing games on, it could be client side, some ppl say csguard crashes it, reformat uggghhh, so on and so on.
I have read hundreds of counterstrike posts and posts in here........I have yet to find a definitive solution
I also tried setting AGP comp driving to manual instead of auto...and set it to DB or BA had minimal success with this tho
Even try decreasing hardware acceleration