The following instructions guide you through changing your Microsoft Office product key or serial number without having to reinstall the Office suite.
After performing the following steps, when you next open an Office application you will be prompted to enter a valid Microsoft Office product key – please ensure you have one before continuing.
Export your Office Registration subkey first
The following registry subkeys (select the applicable one based upon what version of Windows and Office you have installed) should be exported to a safe location before continuing with the rest of these instructions.
For details of how to edit the Windows registry and backup a hive or subkey, see the Windows Registry and Regedit – Basics and Exporting article.
32-bit versions
Microsoft Office 2007
HKEY_LOCAL_MACHINE \Software\Microsoft\Office\12.0\Registration
Microsoft Office 2003
HKEY_LOCAL_MACHINE \Software\Microsoft\Office\11.0\Registration
Microsoft Office XP
HKEY_LOCAL_MACHINE \Software\Microsoft\Office\10.0\Registration
64-bit versions
Microsoft Office 2007
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Office\12.0\Registration
Microsoft Office 2003
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Office\11.0\Registration
Microsoft Office XP
HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Office\10.0\Registration
Deleting the DigitalProductID and ProductID values
Now that you have exported the respective subkey, under the Registration subkey, there may be several Globally Unique Identifiers (GUIDs) that contain a combination of alphanumeric characters – something like {90140300-0030-0A00-0B00-000000CCF1CE}.
Each GUID is specific to a program that is installed on your computer. Select a GUID, and check the version of Office that is listed in the right pane next to the Productname registry entry. After you have found the correct GUID for you version and installation of Microsoft Office, delete both the DigitalProductID and ProductID registry entries by right clicking on each, selecting delete and confirming.
Close regedit and open an Office application. You should be prompted to enter your new Product Key or serial.
