Ok, so you can open more than one window, but unless you have more than one paid account, what good is it? It is not like you can mule like in Diablo 2. From everything I have tried, Blizz shut this down by having the account verification. When you try to log in two characters (even on different realms) it tells you either Account Not Valid or (if you try to log in the same character) A Character With That Name Is Already In Use. So other than eating up system resources, why do it?