Datachk,
Many new computers are sold with TRIAL versions of Office 2007 installed. These trial versions require a product key to start the trial, which lasts for a 60-day period. After the trial period, if you want to continue to use the installed edition of Office 2007, you have to purchase the product and a new, perpetually licensed product key from Microsoft.
So, are you looking for the Product key to start your trial? If so, that should have come with the paperwork that accompanied the new computer.
For great advice on all topics XP, visit http://www.annoyances.org/exec/forum/winxp