Why does my PC restart when trying to use a live CD and flash drive?

view full story

http://askubuntu.com – Recently I was recommended Ubuntu 11.10 64-Bit. I burned the .ISO to a disc and verified it and went to boot it on my PC. When I selected it to boot on the disc, it would get to the menu. As I wanted to try it first, I selected that. My PC then got to the purple screen, went black, and then my PC will restart. So i have burned another CD to the same problem. I decided to try with a USB and i get the very same problem. my PC specs are: Windows 7 64-Bit, 16 GB DDR3 RAM, Sapphire Radeon HD 7970 (21197-00-40G) 3072MB PCIe x16 Gen 3.0 Eyefinity 6 Edition.Is something wrong with compatibility? (HowTos)