I would say try to run some bench marks on your graphics card while the PC CPU is not one of the newest ones, you can stress your Video Card and see what happens also do you have any other games or graphic programs that would stress your video card to see if it has the same issue? If this is happening on multiple programs then probably next step is to see if the cards official forums have any insight maybe some one there can tell you if it is faulty or if your settings are off and it is causing this issue of WoW crashing.