Running 2 Versions of Maplestory on one computer

I have a computer with WinXP but I cannot simply make a new user to run 2 versions of the game (due to reasons I have no control over). Therefore, I am wondering, if there is any other legit way to run two copies of MS under one user account.

Thanks in advance!

Only thing that comes to mind is Virtual Machine, which requires somewhat above average hardware. Really the only way that works best is the multi use accounts.