How can i determine if graphic card is the problem

[mottov2]

a friend of mine asked me for his help.
as soon as he logs into windows, a few seconds to a few minutes later, the thing freezes. Then i start seeing weird sort of like pixelated vertical lines all the way across the screen. I suspect its the problem with his video card, but how can i determine if the gpu is the problem, if it is, how can i tell if its bad driver or just bad hardware?

his computer is a hp pavillion media center.
windows vista 32b
AMD chip..i forget which one it is.
Nvidia Geforce 8900 or 8900 GT.

 

[leorick]

Bad drivers, specially on nvidia hardware will most definitely result in a quick BSOD and the PC will restart automatically. Those vertical lines might be an indication of a failing graphics chip. Only way to test is if you can borrow another card or if you have an on-board graphics just like what ct615 said

 

[wa1]

Yep, try as ct1615 said above...
If his PC fine with onboard graphic then he got a dying/broken card.