Here's my problem. I just modded my xbox with a executer chip, and new hard drive. I have xvox set up already backed some of my games up. Even used my original ms dash and played some of my dvds. Mut all of sudden I can't play dvds or get to my ms dash. it throughs error 21 .I think it's because I made the mistake of trying to get on live and my hdd is not locked. Can somebady help me fix my xbox?