Can BF2142 be installed on multiple computers?

Long story short, My current rig (see sig) fu**** up, and i was tryin to play 2142 on a back-up pc.
my question: can the game be installed on multiple computers? and still be playable on one computer at a time?
I know that u need to register, but would one registration allow it to do so?
I REALLY NEED to know, cause itll be 2 weeks till my real rig can be fixed, and i dont want to have to spend 50 bucks on another copy.

so your saying that the game can only be installed and used under one user acount, and that it is impossible to use the game under 2 user accounts on seperate computers?