Check this out my friend:
https://digiex.net/computing-section/guides-tutorials/consoles/2455-xbox-360-how-get-free-data-migration-kit-copy-content-pc.html
I can't get into an online game. Seems like there is never anyone on it.
You are following this tutorial right https://digiex.net/threads/xbox-360-how-to-inject-into-usb-flash-drive.4072/
It should not matter if its UK or US, it should play on all consoles (It was downloaded by me from the UK). Yes, I think you can play it online with xbox live.
Iv been using an acre aspire one for about a month because our laptop broke so we borrowed it off a friend. Now got the new laptop but I'm looking to buy my own desktop soon.