Information required Thank you for any input

So most of you know some of you dont that i really suck at computer stuff

So the problem is. I gave my friend a lend of Crysis and he thinks its pretty awesome, why not, so now he wants to play online in our server.
He used my CD key to play the game and i dont know if he has different GUID or what the story is there. But he cant seem to play on the same server i am on probably because CD key or GUID is the same.
Is there anyway around this or will my friend just have to buy his own copy
Im also pretty sure iv used my CD-key 4 times is there a limit on this? What is it? And what can i do if exceeded?

Cheers for any help/comment guys

Is mise le meas

How did you and Evil manage to do that Tsopka?

Thanks for the help Guys

Thanks Evil ill take a look now, im sure it'll sort me out XD