Hello sdigian,
The product key affixed to your computer is for Windows Vista (the operating system) and not for Microsoft Office. Many computer manufacturers install a trial version of Microsoft Office. Unless you specifically ordered and paid for a Microsoft Office license, you most likely, have the trial version installed. If you wish to continue to use Microsoft Office, then you'll need to purchase a license (product key) for it.
Please review the following:
How to determine whether you have a trial edition of a 2007 Office suite or program installed: http://support.microsoft.com/kb/927920/en-us
How to convert a trial version of a 2007 Office suite or program to a full retail perpetual license version: http://support.microsoft.com/kb/927756/en-us
Thank you,
Darin Smith
WGA Forum Manager