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Installing an outlook addin for all users

I try to install an outlook addin under HKEY_CURRENT_USER or HKEY_LOCAL_MACHINE depending on the selected installation mode (just me/everyone). So I work with User/Machine Hive in the registry editor.

The installation just for the current user works perfectly. But after selecting everyone during the installation process I can't even activate the addin in Outlook. In the trust center it is marked as inactive and trying to activate it will result with an error: "This add-in is installed for all users on this computer, and can only be connected or disconnected by an administrator".

I'm pretty new to programming in vsto and registry stuff - I'm pretty new to programming in general :)

Any thoughts would be helpful.


2 Answers Found


Answer 1

This is a bit of a minefield, to say the least.  Basically, administrative installs are suppoted for Outlook 2010, but require a hotfix for Outlook 2007.  I recommend inhaling this article and its supporting references:

Deploying your vsto  2008 add-in  to All users  (Part III) - Misha Shneerson - Site Home - MSDN Blogs:


Answer 2

Thank you for this great article!

It actually helped me to get my addin  running for every user  installed on my machine.

Just a brief comment:

According to the article I had to create a DWORD value EnableLocalMachineVSTO in HKEY_LOCAL_MACHINE\Software\Microsoft\Office\12.0. This didn't work  at all. However I realized that there is another Key HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft\Office\12.0... and this did work!

I'm using vsto  4.0 rather than VSTO 3.0, i don't know but this could be the reason for the different key-name.



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