Thank you for your reply but I do not follow. I am not an expert in Excel
but both my ComAddins and my AutomationAddins have extensions .dll as they
are both ActiveX DLLs with a Designer Class (called initially Connect)
(compiled using VB6.0) .

"Bob Phillips" wrote in message
...
By the extension? One is exe, one is xla.

--
HTH

Bob Phillips

(remove nothere from email address if mailing direct)

"David12345" wrote in message
...
Does anyone know how the computer knows the difference between a
COMAdd-in
and an AutomationAddin. The computer knows the difference because it puts
an
entry for COMAddin in the register
HKCU\Software\Microsoft\Office\Excel\Addins but it puts an entry for an
AutomationAddin in the register
HKCU\Software\Microsoft\Office\10.0\Excel\Add-in Manager (if not loaded)
and
in HKCU\Software\Microsoft\Office\10.0\Excel\Options (if loaded). How
does
the computer know to register the COMAddin in a different place from the
AutomationAddin?