PNY GeForce GTX 560 Ti not working. Help?

I just bought the card earlier tonight. I try installing the drivers from the disc but they won't install because I have much more up-to-date drivers. So, I install the graphics card, use the Hdmi-to-micro HDMI adapter that it comes with, and on my tv it always says "No Signal". I've also tried it with a VGA cable and nothing comes up either. With the HDMI cable, the tv stops saying "No Signal" for about 4 seconds but the tv is still black, but then it'll always go back to saying "No Signal".

What could my issue be? I just bought the whole computer back in May, it has an i7 processor, 1TB and a 500MB drive, 12gb of RAM, so I dont know what the problem could be? Maybe not enough power? I hear the fan going when it's running so I would think it's getting the power it needs, but who knows? I have no idea what could be wrong, so any help would be greatly appreciated, thank you!