To authorize your computer in iTunes, open the iTunes application. Enable the menu options if necessary, and select the authorization option. Enter your Apple credentials when prompted to complete the authorization process.Continue Reading
Open iTunes by clicking on the iTunes icon on a Mac computer or selecting the application from the Start menu on a Windows computer.
Click the Store menu option at the top of the application window. If you are using iTunes on a Windows computer, the menu options may not appear by default. To enable the options, press the Alt key on your keyboard to show the list of options. Select Authorize This Computer from the list of options.
When prompted, enter your Apple ID. Enter your password and then click the Authorize button.
Your iTunes account can only be associated with five computers. If you have more than five computers or devices connected to your iTunes account, you must deauthorize an account. To do this, choose the device that you use least to access your iTunes account. Open iTunes and click the Store option, and then select Deauthorize This Computer from the list of options. Repeat steps one through three.