The listing, 100 Microsoft Points!!! has ended.
Using Your Microsoft Points Token:
Your token can be used to add Microsoft Points to your Xbox LIVE Marketplace. If you do not already have a Xbox LIVE account, creating one is easy.
Signing up for a new account
If you do not already have a Xbox LIVE account, it is easy to join and free. Visit the join Xbox LIVE Marketplace website and complete the sign up process.
Redeem your prepaid code
Using your existing Xbox LIVE account you can easily add points using your prepaid code. The easiest way to redeem a prepaid code is to visit Xbox LIVE Marketplace using your web browser.
Visit the redeem token page on Xbox.COM.
If you have not already previously signed in you will be requested to do so by typing in your LIVE ID and password. If you do not already have an account, please read the directions above on how to create a new account.
Enter in the 25 digit pre-paid token you received.
Your Microsoft Point value will be incremented and these points will now be available for use from Xbox LIVE.