Playing DivX or Xvid movie files on the XBox 360. Maybe I don't have the right...

[MattW]

...update? I have read that you can play DivX and Xvid files on the XBox now with a recent update, but I can't seem to find the update. I am new to the 360, and am not familiar with XBox Live or the Marketplace or anything like that. I am able to get on XBox Live and the Marketplace, I just don't know how to get the update. Anyone that could help me play DivX on this thing, I'd appreciate it.