Quote Originally Posted by Greatguardian View Post
You wouldn't be able to just plug and play on any random computer because the computer's registry would be lacking necessary entries. It might be possible to create a batch file or something similar to create the registry entries as if you were installing FFXI without having to deal with extracting/copying the game's files (since they'd already be on your USB drive), but I haven't heard of it being tried.
You should just be able to export a .REG file to hold all of the FFXI registry information, and install it on any computer you want to play on. I can't imagine that there is much more going on in the FFXI install than copying files and adding the registry information, so mimicking an install should be pretty straightforward.