With windows 7 & usb3 port + usb3 flash drive it is easy to put it on & play off there, Easyist way to do it without much explanation is this:
Control Panel -> System and Security -> Administrative Tools ->Create & format hard disk Partitions
Now format the flash drive as part of your system & give it a number, install FF14 from disk onto the flash drive, simple.

NOTES:
*if will remain that drive number on any windows 7 computer so make sure its a high letter like Z: drive
*you will need any nessassary drivers on both computers & latest direct X
*Your my games folder will still be on your standard C: drive but you can move/copy it onto your flash drive & copy onto another computer
*yes it also works with usb 2.0