Once apon a time i was modding happily, freely and just, producing complete masterpeices (

BUT now i have sold my halo 2 and i think i have lost SOME files on my computer.
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THE THINGS I NEED TO KNOW ARE:
*What files would i need to actually run halo 2 on my xbox? Because i think i have all of them ('bink' 'maps' 'media' and the other usual files like defaul.xbe) but i have hardly any of the maps (only main menu.map, shared.map and singleplayershared.map)
*Are there a lot of files located in 'Media'? i only have about 8
I have got halo 2 on games, but it just says there is a problem with the disk i am using.
ANY HELP WOULD BE APPRECIATED!
Thank you so much!
-jon farrar