I'm planning to buy Bad Company 2 for PC but i don't know if i should buy it through Steam or in Ebay, my concern is if i buy the game in ebay will i be able to play in Steam Servers? or I'm gonns have to play in EA servers?
I just Installed the game with a CD Key i bought in Ebay and the Key worked fine when installing the game, but when i want to join in multiplayer I log in in EA and it ask me for Serial Key, so i put the CD Key i used to installed the game and it didn't work
Is the CD Key the same as Serial Key or they are they are different.
That's what you get for buying a key from Ebay. You basically got ripped off and you pirated the software using a stolen key.
Go buy the game and then you should be good. That key might allow you to install the game for single player mode, but it's already registered somewhere else to play online which means you are using an illegal key.
So in order to Play online i need to log in with the EA account that registered the Key to Play Online?
Re-read my post. You have to purchase the actual game. The key you purchased online is illegal. It will NOT work to allow you to play online. Go to a store, go to Steam, whatever and purchase the actual game, not the key. You are playing an illegal copy right now and that is not tolerated here.
Once you have purchased a legal, legit copy of BC2, then you'll be able to play online. Until then, you will receive no further help here because pirating is not condoned at Tom's Hardware.