Have you tried their website–they are pretty good about getting right back to you. Everything plugged in nice and tight? Did you double check all of the connections? How old is your computer? Desktop? Laptop?
My notebook would get about 1 hour into the ride, then gave me the blue screen of death. I concluded this was from overheating from running the graphics. It only took three times (in a row, BTW), to send me to CompUSA for a new machine–kinda bumped the price of the overall CT undertaking. I use it as a dedicated machine.