MS: How to Reset or Change Microsoft Office 2007 License Key

How to Reset or Change Microsoft Office 2007 Product License Key or Volume License Key (VLK)

Close all Microsoft Office programs.

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

Inside, you will find another subkey that resembles the following subkey:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\12.0\Registration\{30120000-0011-0000-0000-0000000FF1CE}

Optional: Backup this registry branch by exporting the Registration subkey to a file, just in case the new product key does not work and you have to restore back the old product key.

Under the Registration subkey, there may be several GUID subkeys that contain a combination of alphanumeric characters. Each GUID is specific to a program that is installed on your computer. If you find additional subkeys that reference Microsoft 12.0 registration, then click and open each GUID subkey to view and identify the Office product version by the ProductName registry entry in the right pane.

For example: ProductName=Microsoft Office Professional Plus 2007

After you find the GUID subkey that contains your Office product or program which you want to remove the existing product license key or registration details, delete the following registry entries by right clicking on the registry entry in the GUID subkey, click Delete, and then click Yes.

Exit Registry Editor.

Run or open an Office application program, such as Microsoft Word or Excel or Outlook. Office 2007 will prompt you to enter a new 25-character product key.

Type in the valid and genuine product key, and then click OK. Then when prompted to choose your preferred type of Microsoft Office 2007 installation, press on “Install Now”. Microsoft Office 2007 will be updated with new product CD key or volume license key, and ready for activation (if it’s a non-VLK serial) or use.