Is there somthing wrong with my xbox 360 or just my games?

I got a xbox 360 for christmas and i think something may be wrong with it. I have 5 games, Baja Edge of Control, Madden 09, Nascar 09, Call of Duty World at War, and MX vs ATV Untamed. Madden freezes at the loading screen, it just keeps loading and never gets to the game. I have taken it back and exchanged it but this copy does the same thing. MX vs ATV Untamed also freezes at the loading screen, this freezes up my whole xbox. None of my friends have these problems, and also my controlers always do that thing were the rings in the middle start going in circles and then they disconnect. I have changed the batteries but it continues. thanks for the help.
also if i send my xbox back to microsoft will i be able to keep my hardrive. If not is there anyway to recover my gamertag and saved files.

Sounds like the problem may lie in your 360, yes. I’d ring microsoft and get their advice.

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