Div x??

Okay so a while ago I put a disk full of movie formats in divx in my xbox, and my 360 got me to download some update so i could watch the formats, since then I have changed 360's as my last one broke but now i cant get it to download the update again? does anyone know what update im talking about and how I can get it again??

Thanks heapssss to anyone willing to offer suggestions!!

Nah man not using a hard drive, using a new memory unit but its all solved now anyway.. for future reference for others I just put a disk with divx stuff on it in the drive, went to the media part on the dashboard changed the source to the disk then tried to play the file, it downloaded the update form there..

cheers for the info though man