Okay, first thing, please dont double post.
 
Second, I see your cpu and video card, but what's your mobo.
 
Do you have Service Pack 1 installed?
Do you have the latest drivers for your mobo, video card, modem, ethernet card?
 
When we say specs, a lot helps if you list the mobo too.
 
Are you overclocking? Do you have at least a 250 Watt power supply? Do you have good enough cooling on the cpu?

Service pack 1 ????

Check the Windows Update site (its in the start menu) and go and apply any updates shown (Sp1 if you dont have it as well as all compatibility updates, etc.)
 
Also make absolutely sure you have the most up to date drivers and try playing half-life in different video modes (D3D GL, and software and see if it runs in any of those)

Yes, there is a service pack for Win2k...dont tell me you dont use the Windows update feature, its usually on the start menu, unless you deleted it.
Getting the service pack will help, but it will take a while to download, so if youve got a 56k modem, start it right before you go to bed. DLS or cable, plan for an hour to download and install, but that depends on how good the speed is.
 
Whats your mobo?

OK I may be stupid. but whats a mobo ?

Motherboard. Its a phrase some of us have picked up, and then automatically assume everyone in nerdland knows it too. My bad.

This one problem frist try editing drvmap.txt
It should look like this
 
-----------------------------------------
Default Default
3dfxVGL.dll 3Dfx OpenGL for Voodoo 1, 2 & Rush
gldrv/3dfxgl.dll 3Dfx Mini Driver
-----------------------------------------
 
?:\Sierra\Half-Life\gldrv\drvmap.txt
 
You should use Glide or aka 3Dfx Mini Driver
 
 
[This message has been edited by SHS (edited 15 April 2001).]

My motherboard is :
 
Shuttle Spacewalker HOT-591P
Chipset : VIA VT82C598MVP
 
and I run HL/CS with 3DFX Mini Driver

Ahh yes, an older Via chipset, and socket 7 to boot. If you've got all the latest drivers for everything and all the patches, you should be good to go, unless you dont have a 250 watt power supply.
 
Socket 7 is just not great for today's gaming, and its not necessarily the socket cpus that are the problem, its the chipsets.
Gigabyte has a couple boards based on an ALi chipset and those boards have caused problems consistently.
 
If youve got everything patched up and the latest drivers, a bad chipset is still a bad chipset and the only way around that is a new motherboard and cpu.
 
Possible problems other than the chipset just being a bad chipset: not enough power--make sure the power supply is at least 250 Watts; something is getting too hot, either the cpu or the voodoo 2 itself is getting past the point of functioning and it hoses up on you---this is an easy fix, just pick up a case fan and/or cpu fan, they're about $10 apiece; also on the voodoo 2, that's a video accelerator and not a full-fledged video card--the fix for that would be to make sure the on-board video or the video card you have has the latest drivers.
 
Question: Is it absolutely necessary that you play CS on a server?
Another thing, is this the only game(s) that crash or do other games and apps do this too?

Well we need atleast full systems specs please it might be you may not have enough ram either.but please list full system specs