I just got myself a new pc, i got steam and legal copies of ARMA 2 and ARMA 2: Operation Arrowhead, i instaled six and it intaled DayZ, but when i try to play it tells me i got "Bad serial number given in setup", i have allready played ARMA 2 and ARMA 2: OA, and i have been playing DayZ on my old pc the day before i got my new one. I don´t understand why it tells me that, and i would be pleased if someone would help me (hope i posted this the right place, im new to the forum)