You will need to set up the partitions correctly if you want to play original xbox games.
This is a really good tutorial that includes the files you need to set it up.
The only files you will need to get is the avatar update for your dashboard because he only includes the the avatar update files for the 9199 dashboard.
http://digiex.net/guides-reviews/console-guides/xbox-360-guides/6517-upgrade-jtagged-xbox-360s-hard-drive-restore-avatars-xbox-1-emulator.html