Outlook 2007 and CDO
Recently I worked on an application that used CDO to open the Global Address Book. The application worked when it ran with Outlook 2003, but failed with the following exception when I used Outlook 2007.
System.Runtime.InteropServices.COMException was caught
Message="Retrieving the COM class factory for component with CLSID {3FA7DEB3-6438-101B-ACC1-00AA00423326} failed due to the following error: 80040154."
It turns out that CDO library is not shipped as a part of Office 2007 setup. If you are using CDO library to access Outlook objects and have plans to move your application to Office 2007, please make a note of this. The fix for this exception is to download CDO library from here and install it!