The notebook PC that I use for work has Microsoft Office Enterprise 2007 installed. Office Enterprise includes most of the applications that I need but not Visio, so I also have Microsoft Office Visio 2007.

The 2007 office products can be used a certain number of times before activation is required and, unfortunately, when I tried to activate my copy of Visio I found that the product key had been used too many times and activation failed (the Office Enterprise key was fine). After watching the number of trial uses of the product slowly decrement, I needed to change the product key, but didn’t want to have to re-install Visio.

Microsoft knowledge base article 895456 provides details for changing the product key for the 2007 Office system (as well as other releases).

It’s important to note that:

• For a 64-bit version of Windows, the registry location to edit will be HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Office\version\Registration rather than HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Office\version\Registration.
• If multiple Office products are installed, multiple GUIDs will appear in the registry – the important entry to look at will be the ProductName – in my case one GUID had a ProductName of Microsoft Office Visio Professional 2007 and the other had a ProductName of Microsoft Office Enterprise 2007.

Once the correct GUID had been tracked down and the associated DigitalProductID and ProductID entries removed, I fired up Visio, entered a different product key and successfully activated the software.