Playing movies w/ external hard drive: "media update"?

[sprog84]

I was told that I would be able to play movie files from my external hard-drive through my xbox. My movie files are all .avi .

But when I tried, it said that I needed a "media update", and that I needed to go through Xbox Live.

I don't have Xbox Live, and I don't even have internet access in my room.

Any suggestions on how to get these media updates to my external without having to go through xbox live? Could I download them somewhere and upload them with a USB drive? I'm not really sure how this works, so extra details are more than welcome!

Thanks!!