Ok recently my xbox360 has been playing up, I have to open and close the tray about 30 times before the game works... anyway instead of fixing it as its quite an old xbox360 I decided I'll buy the xbox360 slim...

If I buy a new xbox360 will I be able to access my xbox live account from the new xbox, also would I be able to play the same games such as Modern Warfare 2 on the same level as my old xbox? Like currently im on level 38 on MW2 after I log in through the new xbox will I be on the same level or will I have to start all over again?
Wow thanks everybody for taking the time to answer that, its put my mind at ease now