The addin is a DLL and is installed either where the user selects or where
you force it to be installed, depending on your installer. If you know the
DLL name and ProgID you can always find it's location in the registry.

The DLL can only be updated when Outlook isn't running and must be
registered if any CLSID's or interfaces have changed so Outlook recognizes
it.

I check an XML file on a Web site to get the latest version and then I use
Win32 API calls to download the newer installer if there is one. I then tell
the user to close Outlook and run the installer, the installer checks to
make sure Outlook isn't running.

--
Ken Slovak
[MVP - Outlook]
http://www.slovaktech.com
Author: Absolute Beginner's Guide to Microsoft Office Outlook 2003
Reminder Manager, Extended Reminders, Attachment Options
http://www.slovaktech.com/products.htm


"Dewey" wrote in message
...
Hi
Suppose I make an add-in for company-wide distribution, then I want to
update it later. Is there a way to have an add-in check an intranet
server
for an update and automatically install itself?
If not, where is the dll stored on a user's machine so I could manually
replace it? Would it be possible for the add-in itself to do that while
running, or would it need to be stopped and replaced by a different
utility?

Thanks for any help
-Josh