ephox (DayZ)

Hi, Ich bought Arma II here: http://www.gamesrocket.de/download/Arma-2-Black-Edition.html Then i got this Key: N0GL-469R5-xxxxx-P1AJ8-xxxxx After this I installed Arma II Black edition. Installed Six Updater & Launcher. Started Launcher, joined a server. After 15 seconds I got this error: bad serial number given in setup :s I already tried starting Six Updater first, then Six Launcher. Still the same problem. What could i do to solve the problem.. ? €: Arma II is installed without steam!

Aaaaaaaaaaaaaaaaaaaah Why!! So i need to download arma II demo and buy oa?

I have bought a ARMA II key. Now i need ARMA II OA. Could i install the demo in steam?

Is operation arrowhead for free?