You’ve authorized 5 computers with your email ID already There’s something wrong with your Apple ID/iTunes sign-in There’s something wrong with iTunes/some file.
There can be three main reasons why iTunes refuses to authorize your computer. After click 'Authorize this Computer', you need to enter your Apple ID and password, and click. And tap 'Store' 'Authorize this Computer'. For windows users, you may hold down the 'Control' + 'B' keys on keyboard to open the iTunes menu list. For Mac users, go to 'Store' 'Authorize this Computer'. How to authorise your computer in iTunes: Authorising a Mac To authorise a Mac, sign into any 'Authorize This Computer' dialog, using your Apple ID and password.