I bought an Orignial Xbox game and a 120GB Internal Hard Drive for the Slim. I did every thing the forums said to do but the error message keeps coming up and says "The game couldent start. Try downloading the game again." But I did not download it, the game is a disk. I am not sure what else to do, but some forums do say to have an HDD hard drive so I have no idea if I bought the right one.