Hey, does anyone know if COD5 can be played co-op over a LAN? Also, can I play it using the same disc or will I have to buy two copies if I wanted to do this? Also, assuming the game is on Steam, could I theoretically buy the game on steam, download it to PC A, then log in on PC B, download it there too, and then play Co-op over a LAN in offline mode? Sorry if this is blatantly wrong, I'm new with Steam. Any help will be greatly appreciated, as this is the difference between buying it for 360 and playing splitscreen or buying it on the PC and play over LAN, which is preferable. Thanks!

So if I just buy one copy of the game retail and install it on two PC's, I WILL be able to play campaign co-op over a LAN? It's not going to check the CD keys and say "You can't play because you are both using the same CD Key?" I'm talking about campaign specifically co-op. I'm not worried about both playing multiplayer online, as I know what happens with that. Can anyone confirm this is 100% true? Preferably from doing it themselves.

Try it?

So Co-op will work for LAN on COD5 too? I can't try it myself because if it won't work than I will buy it for the 360. I'm not going to buy a copy for the PC, try it, and if it fails then I half to buy another for the 360 so I can play co-op.

cod 4+5 never does CD checks for LAN so u only need one game.

cod5 needs two copies of the game for LAN gaming. It's checks the cd key and will notplay if two are the same.

Annoyingly, I re-installed the game on my friends pc with a different cd key but it still says that we have the same cd key when we try to play coop.

I have checked the reg entry for cod5 on both pcs and the cd keys in the reg are completely different from eachother.....

We have since ended up buying a second copy of the game, which kinda sucks!

We weren't connected to the internet at all. It was down for about a week when we got COD5 and we still had problems starting COOP.

So, even though we weren't connected to the internet and the cd keys were different in the reg, the game wouldn't allow COOP.

Is there any possibility that the game can tell that both installs were from the same cd?

no clue how to work the CO-OP! kinda frustrating!! i used one game with same CD key, wont allow me to play, said ur CD KEY been used on another computer, then i tried another CD key, it said the same problem, i tried abt 5 different CD KEYS and STIL the same F**KING prob!! piss me off! if anyone get it working, please let me KNOW HOW !!!!!

I think it's really stupid they check CD-keys on LAN. Doing this kind of crap makes me want to just pirate the game and play LAN whenever I want. Who are they to tell me, despite having paid money for their game, that I can only install it on 1 PC? I have 3 PC's at home and if I want the game on all of them, it should be allowed. Even if I gave the game to all my friends to install for LAN, they still wouldn't be able to play online. It's alot of BS.

It sucks coop. We are on a remote site (no internet connection), but have 6 PCs to play against eachother on a LAN. We HAVE 6 LEGAL versions of COD5, but still it gives the CD-key error and kicks everybody off!!!!! Checked everything, but no succes.

So you just need a one time internet connection to verify the keys, or do you need the internet connection all the time?

Yeah, the first thing it does is start doing crap on the internet. It's like a pop-up thing that blocks the main menue for a few seconds.

Yeah, im having the same problem. My buddy and i bought our own copies of the game (retail). I can see his COOP server, but it tells me the session is no longer available if i try to join it. It finally let me in the lobby when he invited me to the game though the friends list, but it still wouldnt let me play! Said my cd key was already in use. I can join any multiplayer game, even his if he puts one up! Just not COOP. Really dissapointing, since that was one of the main reasons i bought it. Surely there is something I can do to make it work.

Im running version 1.3.1080 by the way. I'll let you guys know if i have any luck.