I think thet OP means with a EQ2 reloaded and upon entering the CD key to activate the program, it reports the key has been already used?
According to
this post, the CD key is used only once. You should still be able to log on, and your characters are still in the system.
I don't remember if the CD key was required to install the program or activate the account.
That would be good to know, since I plan on upgrading my MB soon, and will require either a new hard drive or format my current hard drive.