If you are running Microsoft Reader on Windows Vista® operating system, please follow the instructions below to activate

Select the URL below, right-click and select copy 
http://das.microsoft.com/activate/en/default.asp

In the Start Menu, click on All Programs, right-click on Internet Explorer icon and select Run As Administrator

Click Allow if you get a User Account Control credential prompt (if you are not running as local administrator, you may be prompted to enter administrator credentials)

Right-click in the address bar and paste the URL. Press enter
Now click the "Sign In" button to begin the activation process

Note: After Microsoft Reader activation is completed, please close the elevated Internet Explorer window.