So I recently purchased a new Xbox 360 HDD for my old Premium since my 20GB was getting WAY too full. I swapped everything out and so far everything worked great. That is, until I tried to play an Original Xbox title from disc. I tried Halo 2, Mechassault 2, DOA, and I kept getting the same error every time: "The game couldn't start. Try downloading the game again." I contacted an Xbox Ambassador and the dude was awesome, but totally stumped. We then got a logic chain going and I theorized that if I swapped drives again and hooked up my old 20GB to it. It INSTANTLY allowed me to play old-school games and I was able to re-play EVERY Original Xbox game that I had. I would recommend passing this around to every gamer you can think of that still plays the old games and has this issue.