WHAT IS AUTHORIZATION?
Up to 5 computers can share one MSN Music account. Authorizing a computer allows it to play music that you have purchased from MSN Music. During sign up the computer you use is automatically authorized. The only time you'll need to manually authorize a computer is if you want to play your music on a second, third, fourth, or fifth computer.

AUTHORIZING ADDITIONAL COMPUTERS
There are two ways to authorize additional computers. The simplest way is to copy your music to the other computer and attempt to play it. When you attempt to play songs you'll see the following dialog. Just click "I already own this song", enter your sign in information, and the PC will be automatically authorized. Licenses for all songs you've purchased will be synched to this computer so you only need to see this dialog for the first song you attempt to play.

The second way to authorize additional computers is to go to the My Account page and choose Manage My Computers. You can then click Authorize to enable that computer to use MSN Music.

WHAT IS DE-AUTHORIZATION
De-authorization is your way to manage whether your music will be playable on a computer. You are able to authorize up to five computers at once to play your music collection.  De-authorization takes that privilege away from the computer. You should de-authorize a computer when you are replacing it or when you no longer want to purchase or play your music on it.

HOW DO I DE-AUTHORIZE A COMPUTER
De-authorization must be done from the computer being de-authorized. If that computer is no longer accessible to you you will need to contact MSN Music Technical Support to have them de-authorize that computer for you. If you use shared profiles with Windows XP de-authorizing will disable MSN Music from all profiles. To de-authorize go to the My Account page and choose Manage My Computers. On that page click the de-authorize button.

Note:
Windows Media Player 10 only:
You can re-authorize and de-authorize the computer as many times as you choose.

Windows Media Player 9 Series and earlier versions:
De-authorizing a computer will de-authorize your collection of music on that computer permanently.  It will not limit your ability to authorize your music on any other computers.

If you meet the minimum system requirements, we recommend you upgrade to Windows Media Player 10.