If you used Visual Tools for Office (VSTO) to build your add-in that is
Outlook 2003 only. If you didn't use VSTO and you have a "plain" .NET add-in
then check to see if the v.10.0.4504.0 Outlook Primary Interop Assembly is
registered on the XP/2002 machine. Also, if your add-in tries to call 11.0
(Outlook 2003) properties or methods while running against Outlook 2002 it
will throw exceptions so you'll either need to catch those or, better yet,
identify the Outlook version you're running against and don't make calls
that the COM object can't accept.

wrote in message
oups.com...
Hi Ppl,

I have an add-in that adds a button to the toolbar, etc.
It installs and works seamlessly for Outlook 2003 but is nowhere to be
seen for Outlook XP.
It was developed using VS 2005 and Outlook 2003.
Is there a way to get around this other than creating seperate versions
of Add-in for Outlook 2003 and XP??

Thanx