Counter Strike Source problem

[BORN A REBEL]

Ok so my problem is that, I can run Counter strike source fine but after a bit it just frezzes and I cant do anything not even you task manger, the only option left is for me to hold the power button and shutdown. And other steam games run fine expect counter strike and the wired thing is that I installed new drivers for my card and after that failed i rolledback still didnt make a difference, so i uninstalled counter strike reinstalled it and this didnt work too.

 

Windows 7 x64bit

 

Computer Specs

Ati Radeon HD 5970 Saphhire

Cpu Intel Core i7 920

8 gb ram ddr3

 

 

Please Help

 

EDIT

I just got this error rrecntly and it says engine error failed to lock vertex buffer in CMeshDX8::LockVertexBuffer

[SchmoSalt]

Hmm, according to Valve this may be a problem with your drivers or not having enough paged pool memory free.

 

https://support.steampowered.com/kb_article.php?ref=9404-WRDH-5396

 

I'm guessing it's probably the drivers. When you tried to install the new drivers did you uninstall the old ones, reboot, install the new ones, then reboot again?