I have a GTX 670 and i7. Everything has worked for the past few months since I built it. Not a single problem. I had just downloaded the WoW PTR when my computer shut off. I don't think anything would've overheated considering what I have and the fans I have. I couldn't tell you how hot it was running or if the fans were going crazy, but I normally run very cool. I tried to start my computer back up and it was fine...until I started the PTR back up. It turned off as soon as I clicked play. So if the PTR is the problem, and it is, then I'd just delete it and not play it...right? Well, I can't do that. My computer will not start up now and the GPU fans appear to be going at 100% speed as soon as I turn it on, but windows is not starting and my monitors are staying black...I've waited an hour now to see if maybe it had to cool down, but still no luck. Please help!