HKLM entry for Excel VSTO not working RRS feed

  • Question


    I have been deploying an Excel add-in developed in VS 2010 for Excel 2010, for over six years, on over 300 machines. All machines are Win7 64 bit. I add the registry keys to HKLM\Software\Wow6432Node\Microsoft\Office\Excel\Addins.  Up to now, I haven't had an issue installing onto new machines.

      We aquired another company and have been deploying the add-in.  Again all Win7, 64 bit.  Three machines out of thirty had the same Isuue.  They wouldn't run with the HKLM key entry.  If fact, Windows Installer won't make the entry, I have had to entry it manually, even then, it would not work. The add-in only runs when the add-in key entries are made in HKEY_Current User\Software\Microsoft\Office\Excel\Addins.  The machines having the problem are fairly new, never had anything less than Office 2010 on them. All users have administrative priviledge.  The addin program itself loads into Program Files(86).  I've read the articles Deploying your VSTO add-ins to All Users and Registrt Entries for Application=Level Add-ins.  The only issue mentioned is the need of fix 976477 which seems to only have to do with Office 2007.               What could be causing this issue ?      Thanks

    Friday, February 26, 2016 11:24 PM


  • Hello John,

    Do you have the Click2Run edition of MS Office installed on the problematic machine?

    Click-to-Run is a software delivery and updating mechanism. Products delivered via Click-to-Run execute in a virtual application environment on the local operating system. This means that they have private copies of their files and settings, and that any changes they make are captured in the virtual environment. Click-to-Run is fast—users can start running an application within a short time without waiting for the entire product to finish installing. Updates are carried out automatically in the background, without requiring a user to first remove an installation or install patches. Click-to-Run products are virtualized and do not conflict with other installed software.

    However, because a product delivered by Click-to-Run has private copies of all its files and registration, an add-in developer cannot determine the product's existence the same way as a product that has been installed on a client computer’s hard drive. Starting in Office, Click-to-Run is the default mechanism to deliver Office, and only a subset of Office customers can request physical media to install Office. Add-in developers should determine whether Outlook has been installed, and whether Outlook has been delivered as a Click-to-Run product.

    In Office, 32-bit Office and 64-bit Office are available via Click-to-Run. The default delivery is 32-bit Office for 32-bit or 64-bit Windows. You can also obtain 64-bit Office for a computer with 64-bit Windows. If you would like to have both Office 2010 and Office on the same computer, the bitness of the two versions of Office must be the same.

    For example, to check whether Outlook was delivered by Click-to-Run on a client computer:

    • Verify if the VirtualOutlook key exists in the following location in the Windows registry:
    • The VirtualOutlook key is a REG_SZ value that contains the culture tag of the installed product language, such as "en-us".

    Also you may find the Deploying an Office Solution section in MSDN helpful.

    Saturday, February 27, 2016 2:10 PM