cd key help...?

I got key from friend and when i enter it ,i get this error -limited-use key ?

it depends, it could be ether a beta key that was floating about in your friends collection, or the key used for the Free PvP event....
if thats the case, you will have to wait for another Free PvP or PvE weekend event to use the key.....check the GwGuru search for the Free GuildWars Event Key, im sure the trhead is still there....
if the key your friend gave ou matches ether the European or American Free key, thees your answere

when i register it ask for e-mail .does it have to be same as my friend use ?i mean does every key can be registered on only one e-mail adress .... ?

Um. CD-keys are one time use only, if it has been used, you can't use it again, what'd be the sense to even buy the game if you could just give around your own CD-key.

hmm i got 2 friends shering the key ...one play at night and one at morning ,diferent compuers ...

they will be using the same account, 2 characters each ot something... CD keys CANNOT be used again!

yup, each key (appart from the Free Event CD keys) is single use....
same way if you used your mates key for neverwinter nights and he was on with his copy, you would be told 'cd key is in use, try again later' when trying to go multiplayer online.

IF (and thats a big if) you were sharing an account thru mutual consent, he would have told you that the password and e mail would be the same on his as on yours (like the daytime and nighttime players sharing one account)
otherwise.....

again, have you checked to see if the key is the euro free key for Events like the PvP free weekend...

yeah i fixed it ,got a new cd key ...now its working perfectly

thx for help