There is so much wrong with this post from grammar, vocabulary to statements made. You can still play LAN games, use third party software to tunnel LAN games over the internet or connect directly to a known IP address over the internet, and if you want a server list for Arma2 you can activate your CD-key on Steam.

what cd key?

go to your account > games > Arma 2. There you have it.

That long ass key that's there doesn't register on steam. If you've tried it and succeeded, please tell me where I went wrong. Thanks

Look closer. There are two distinct CD-keys in those three lines. I don't know what the last sequence of numbers are for, but I guess it has something to do with the CD-key changer program that comes with the GOG version of the game. I have not tried redeeming the keys on steam as I originally bought the games there a couple of years ago before picking them up on a GOG sale, but I believe one key is for ArmA2, the other is for Operation Arrowhead.

You're right. Thanks. I never would have spotted that without you pointing it out.

To help anyone else: The 2 keys are in the first line. Look for the break between them.

This is so stupid. I have no idea on why they removed ARMA II from gog. its a heresy because I dont want to have steam if I want to play ARMA.

The developers have set up a Server Browser page to use in place of the in-game server browser. This is especially useful for the earlier Arma games which are not going to be patched.

You can just go offline in Steam and moreover you can just play a version of ArmA (1.62 or before) that doesn't use Steam. You won't be able to play online though as they use the Steam servers for multiplayer.