In the 64-bit edition of Office 2010, 32-bit COM add-ins that are installed are not displayed in the COM Add-In dialog box

Applies to: Office Professional Academic 2010Office Home and Business 2010Office Home and Student 2010 More


When you try to install a 32-bit application COM add-in to a 64-bit Microsoft Office 2010 application, such as Microsoft Word 2010 or Microsoft Excel 2010, the add-in is not present in the list of add-ins for the application. If you try to load the add-in by using the COM Add-In dialog box, you receive the message that the add-in is not a valid add-in.

If you check the registry entry for an installed add-in, the LoadBehavior value for the add-in is set to 16 (decimal) or to Load first time, then load on demand. However, the add-in does not load when you start the Office 2010 application.


This issue occurs because the 64-bit editions of Office 2010 applications do not run 32-bit COM add-ins.


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.