XI really doesn't like being a "portable" install, as in you can't just plug/copy it over and expect to play it without some crap happening. You'll need to register a number of its dlls with regsvr and put in entries into the registry, essentially mimicing an install process. It does work as I've done this in the past, though that was years ago and I no longer have that install nor the files I used to make it happen (just a couple small .bat and .reg files you'd run in the ffxi folder). Here was an old thread detailing some of this:
http://ffxi.allakhazam.com/forum.htm...37895217382813 There's probably a few more posts about this here on bg somewhere.
add: although that makes me think someone could probably
sandbox it, like I've seen some programs get turned into portable apps by isolating them with sandboxes. Seems more than possible to do this, but have 0 desire to really look into it.
You could also try running it in a
virtual machine, essentially just copying the VM's vhd, setting up the hardware profiles, and giving it a go. Most don't tend to deal with 3d-acceleration well but game is pretty damn old and will probably need virtualization to even run in the future.