Thanks to Windows having to be reinstalled when you add/rearrange the video cards (thanks Microsoft) I've had to perform a clean install when adding a new graphics card. Okay, fine, the only problem? The computer keeps shutting down when I mine!

I have a 1200 watt power supply that is Platinum rated, two GTX HD 7950 cards, and one GTX HD 7970 card. The current hash rate I am getting is 54, and 72 for the two 7950, and around 600 for the 7970. Before installing the second 7950 the usual hash rate was around 300+.

Also, because that's not bad enough, the computer quicks working, and I have to restart it to get anything on the screen to come back up. If anyone can help me figure out what is wrong I would greatly appreciate it, because this is beyond weird.