Check your Vid drivers and your DX install. I play CS flawlessly on my machine, and never had such an error, so the problem is HW related somewhere.

Many things can cause that error. One is an exploit that people are using to crash half-life clients.

If that is the case, it should be fixed in the next half-life update...due in a few weeks

The exploit, as you call it, crashes servers, not clients. I still maintain my previous comments.

not "THE" exploit, "AN" exploit. There are many, and they can crash clients.
 
The other day I was playing on a 16 player Internet server with 3 other people on the LAN sitting next to me. We got into an argument with someone who was, lets just say not being very polite. He left the game then suddenly everyones screens came up with that exact error message. I restarted half-life and re-joined the server. The server was empty. I typed 'timeleft' in the console and there was only 4 mins left of the map, which proves all the clients crashed but the server remained. It was most likely that player used some kind of crash exploit.
 
That doesn't mean you can't crash individual clients. If you look through the half-life/counter-strike changelog history, you will often see a 'fixed client crash exploit' for each new version.
 
However, yes, also try Ronin's suggestions, as It is not necessarily an exploit.