Deauthorize Your Computer

Apple lets you play your iTunes Store purchases on up to five computers. You won’t be able to play purchased music, books, or videos on a sixth computer if you try to authorize it. That’s because Apple’s authorization system will see five other computers already on its list and deny your request.

To play protected files on Computer Number 6, you have to deauthorize another computer. Choose Store→Deauthorize Computer from the computer about to get the boot, and then type in your Apple user name and password. The updated information zips back to Apple.

Are you thinking of putting that older computer up for sale? Before wiping the drive clean and sending it on its way, be sure to deauthorize it so your new machine will be able to play copy-protected files. Erasing a hard drive, by itself, doesn’t deauthorize the computer.