Graphics card problems

[Dist]

My brother for the last couple days is having issues with this 8800GTX, he is getting artifacts and crashes with a warning about the display driver crashing but windows managing to recover or something.

Are there any programs that can check if a graphics card is healthy or if it is on its way out?

Also, what is something that is similar or better than the 8800GTX in terms of GPU power, but without costing too much as it needs to be fixed but we don't really want to be any worse off and saving money is more important than having a super high end card.

 

[Dist]

All my brother wants is something that can play games like tribes vengence, world of tanks and diablo 3 on his 30'' dell (which he doesn't even run at ultra high rez). He doesn't even need to be able to run stuff on high settings. He wants to stay well within the sub £100 range, preferably closer to £50 (which I think is perhaps pushing it, but running games like diablo 3 only list a geforce 7800 as min requirements, and geforce 260 as recommended, so it could be possible within that budget).

 

[Dist]

My brother is currently looking to order http://www.overclockers.co.uk/showproduct.php?prodid=GX-264-AS&groupid=701&catid=56&subcat=1982 (doesn't want to wait for any pre order cards, and this is ideally around the max he wants to spend).

Good card for gaming? (again, he doesn't need to run any games at max, just needs a good replacement that performs as well or better than an 8800gtx.)