bekanntlich verhindert ja Office 2007, dass VSTO-AddIns (managed Code) von HKLM geladen werden. LoadBehavior wird dabei immer wieder auf 2 zurückgestellt.
Das Office Team hat jetzt (nachdem Office 2010 das sowieso wieder erlaubt) auch einen Patch für Office 2007 herausgebracht, der diese Möglichkeit wieder erlaubt:
A 2007 Office system application does not load an add-in that is developed by using VSTO
Beachten sollte man allerdings, dass der (Standard-) Benutzer diese AddIns nicht deaktivieren kann!
In Microsoft Office 2003 and earlier, COM add-ins could be registered in HKEY_LOCAL_MACHINE and this had the following effects:
• They were available for all Windows user profiles
• They did not appear in the COM Add-ins window so therefore the user could not remove the add-in.
In the original version of Office 2007, this behavior was changed so that add-ins developed using Visual Studio Tools for Office (VSTO) and registered in HKEY_LOCAL_MACHINE would not load. In addition, Office 2007 was originally designed so that other add-ins registered in HKEY_LOCAL_MACHINE would appear in the user interface and could be disabled by using the COM Add-ins window.
After installing the hotfix and enabling it using the EnableLocalMachineVSTO registry key, add-ins developed using VSTO will load. However, by default they will still be displayed in the user interface. These types of add-ins can be optionally hidden in the COM Add-ins window by deploying the DontDisplayHKLMAddins additional registry key. For more information, see:
929590 Known issues when you develop custom solutions for Office Outlook 2007
The end result is that by deploying both the EnableLocalMachineVSTO and DontDisplayHKLMAddins registry keys, Office 2007 will now revert back to Office 2003 (and earlier) behavior for VSTO-based add-ins. The only difference is that the add-ins will be listed in the new Office 2007 Trust Center. However, users will not be able to remove them because they will not appear in the COM Add-ins window.