iTunes Authorizing and deauthorizing a computer will allows us to manage to sync your contents with your system and iDevice. So you can store your purchases in your authorized computer to sync with your another iDevices. Apple allows us to Authorize only 5 computers for the iTunes. When you are adding another computer for authorizing, you should deauthorize the previous system. You need your Apple ID to authorize the computer.
You can simple Authorize or deauthorize your computer from Store option in iTunes menu bar. What if we have to deauthorize our old computers?. Yearly once i used to change my laptop, i forgot to deauthorize old computers when i sold that. So i followed these steps which i am going to show you to deauthorize my old computers.
First You need to Open your iTunes which you are using currently.
Select Store Menu and Select View my Account
Sign in with your Apple ID and Password
You can See “Computer Authorizations” Section. Under that you can see all your authorized computers are listed. Click “Deauthorize All” button to deauthorize all computers. (This action only avaliable once per year and Apple won’t allow us to deauthorize single computer, So we have to authorize again which we needed.)
If you have any doubts regarding this topic, Kindly drop the queries in the comments section.