Just thought I'd share this. Apologies if I'm teaching you how to suck eggs.
To update your Xbox without connecting to the internet (useful if your box has been "modded")
Follow the instructions here. Basically download the file and extract the contents to the root of a USB stick or CD/DVD.
http://support.xbox.com/en-us/pages/xbo ... .aspx#burn
I updated mine this morning and I can now play divx and avi files I have downloaded. Plus the interface has been changed dramatically.
Happy gaming!







