Before you can activate your software you will need to retrieve your Product Key. To do so you must follow these steps.
Enter your 25 or 27 character alpha-numeric PIN found on the inside of the card attached to the back of your Office for Mac 2011 box. NOTE: Your PIN cannot be used to activate Office for Mac.
The product key is a 25 character alpha-numeric code printed on the back of the card located inside the package.