If you don't know this yet then keep reading this Tutorial how to turn on 2 or more Maplestory on 1 computer.

#1. You gotta have at least 2 or more users accounts on your computer
(If you have the user Guest on your computer put your maplestory folder in public documents.)

#3. Then turn on Maplestory for your first user account and login to your Maplestory account.

#4. Alt tab and goto start and press Switch User

#5. Then goto your others users accounts and do #3 and #4 until you finish turning on maplestory on all your users accounts you made.

#6. If you have different kinds of accounts that are over lvl30 or lvl50 do cpq (lvl30-50) or the other cpq (lvl51-70) and do free wins or ariant pq (lvl21-30) and do free wins. Or use your high lvl accounts to trian your low lvl accounts.
Or something.