Info on AddIn help.
Firstly, I highly recommend the tool AddInSpy. This tool will detect the
COM AddIn's prerequisites and loading errors. Please download it from,
It has a friendly WPF GUI that can report every AddIn's status. For more
information, please read,
As to the issue itself, since the AddIn does not appear in the COM AddIn
Dialog, it looks like a COM registry issue to me. So my guess is correct,
we can use Process Monitor to listen to the msiexec's registry actions
during the installing. Then we may find some useful information to narrow
down the problem.