I have a PC, specs in the signature, that is way overpowered to play world of warcraft and I've been playing a lot. Today, however, I have been crashing all day with annoying frequency, getting this message:
That's a TDR reset message. It means that your GPU has hung or crashed and was reset by Windows. Make sure your temps and voltages are OK (particularly on the 12 V rail). Also a recent driver update can cause this, so you can try rolling back to a previous version.