Question : Problem: How does iTunes identify a computer?

iTunes allows 5 different computers to play songs bought from iTunes, but how does iTunes identify a computer?  Does each computer have a unique id?  Does it identify with the Windows installation product key?  Does iTunes identify with the hard drive?  If so, if my library of songs is on an external hard drive and I use the same hard drive on another computer will I have to authorize that computer?  If I format a computer and reinstall Windows and iTunes will I have to authorize the computer again?

Answer : Problem: How does iTunes identify a computer?

Declan_Basile,

>> but how does iTunes identify a computer?  Does each computer have a unique id?  <<

I haven't seen that iTunes publicizes this so I can't say for sure.  However in almost all the cases I know of things like this are done with key hardware identifiers.  Not just one piece but a few.  Thus each computer's "unique" id is actually made up of a few parts of that computer.  This allows a part of two to change without an issue and a better chance of a unique identifier.

The Windows key and the HD alone are not the identifiers to my knowledge.

>>  If so, if my library of songs is on an external hard drive and I use the same hard drive on another computer will I have to authorize that computer?  <<

Yes.  The identifier isn't just on the HD.

>> If I format a computer and reinstall Windows and iTunes will I have to authorize the computer again? <<

Yes.  The authorization is stored on the computer.  If reformatted and reinstalled that would certainly be lost.

Let me know if you have any questions or need more information.

b0lsc0tt