the maXIMUM NUMBER OF FREE accts have been activated on this iphone

Any one device can create only 3 separate iCloud accounts. This is tied to the device itself, not any user accounts. Once you have reached this limit you can only create another account by using another device - once that is done you can sign into the new account on the original device.

Why have you been creating these accounts - is it deliberate? I just wondered whether you were doing this by accident when trying to sign in.

If you sign in with an ID which has already been used to create an iCloud account you will be signed into that account. If you try to sign in with an ID which has not been used to create an iCloud account then a new one will be created (up to the limit of three).

Are you talking about 'iTunes Match'? - this is for uploading songs other than those purchased in iTunes and coasts $25 p.a. so you'd know if you had it. It's nothing to do with iCloud; that and re-downloading of purchased items require you to log into your iTunes account. iTunes Match requires iTunes 10.5.1 minimum.

If you aren't talking about these, but simply about music files you have, you can't do this with iCloud, which has no general file storage. You could network the Macs, or use Migration Assistant (which you will be offered when you first switch on a new Mac, with instructions).

hello.. it also happened to me.. i created it by accident.. so is there any possible ways to undo it?

You cannot 'uncreate' an iCloud account. I'm afraid your only option is to create an account on another device.