This authorization system is a form of DRM, and it restricts access to the content you purchase on i Tunes.
On Mac, click the Store menu and select Authorize This Computer.
Sign in with your Apple ID to complete the process.
Your computer will then be able to download, sync, and play your purchased i Tunes content.
You’ll also find a Deauthorize This Computer menu option in the same place.
i Tunes uses an authorization system to ensure only a handful of computers can access your purchased music, videos, and other content at any given time.
You should deauthorize i Tunes before getting rid of a computer or reinstalling Windows.The authorization system is a form of DRM, so it involves jumping through hoops.It’s supposed to limit access to your purchased content.You must authorize a computer — Mac or Windows PC — in i Tunes before that computer can download and use your purchased movies, TV shows, music, e Books, audiobooks, apps, and other content. The majority of music files on i Tunes are DRM-free, so you don’t have to authorize a computer to play them.You can have a maximum of five authorized computers tied to your Apple ID at the same time.Macs and Windows PCs both count towards this combined total.