David Bayer,
Thank you for contacting the Windows Genuine Advantage (WGA) program forum. You issue is very important to us. Please submit a service request with Microsoft Product Support. I'm afraid this is not something I can handle here in the forums. I have a feeling that the missing Product Key is going to be a real problem for you. Try opening the support request, explain your situation, include your Live ID/Email you used to register your Office program and serial number. This may or may not help you - I'm just not sure.
http://go.microsoft.com/fwlink/?LinkId=52029
I know this comes a little late in the game, it is important to hold on to all documentation and Product Keys/CD's/DVD's in relation to your newly purchased computer and Microsoft Products. Important to keep these in a safe place. Same goes for hardware. If this is old news, new news, this is an important reminder. Post back here if you still have issues, and we'll try to think of more options.
Thank you again for contacting us in the WGA program forums. We're here, for you.
Rick, MS