Deauthorizing a computer allows you to manage which computers can play music, videos, audiobooks, or other content purchased from the iTunes Store. Authorization helps protect the copyrights on the content you buy. You can use your digital rights management (DRM)-protected music purchases1 from the iTunes Store on up to five different computers (these can be any mix of Macintosh or Windows-compatible computers). When you play an item you've purchased, your computer is "authorized" to play content purchased using your Apple Account. Note: Songs you encode in AAC format from a source other than the iTunes Store, such as your own audio CDs, and songs from iTunes Plus downloads do not need to be authorized.
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