Change Office 2007 Product Key

Follow these steps:

1. Close all Microsoft Office applications.

2. Click Start, click Run, type regedit in the Open box, and then click OK.

3. Locate the following registry subkey:
HKEY_LOCAL_MACHINE\Software\Microsoft\Office\12.0\Registration

Note You may also find another subkey that resembles the following subkey:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\12.0\Registration\{91120000-0011-0000-0000-0000000FF1CE}