If you’ve authorized iTunes on different computers over the years, it’s annoying when you run out of the five that Apple allows. Here’s how to deauthorize all five computers at once.
Launch iTunes and open the iTunes Store. In this example I’m using iTunes for Windows. On the main page under Quick Links, click Account.
Type in your Apple ID and Password. Click Account Info.
The Account Information page comes up. Under Apple ID Summary, click Deauthorize All.
When the verification window comes up, click Deauthorize All Computers.
Success. All five computers have been deauthorized. Click OK.
Now you’ll need to reauthorize the computer(s) you’re using. Click Store >> Authorize This Computer.
Type in in your Apple ID and Password. Click Authorize.
Successful! Click OK. You can now authorize up to four more computers. Just like starting over – Groovy!
Note: Apple allows you to deauthorize all five computers only once a year.