A VSTO addin compiled under Outlook 2003 will run unchanged on Outlook 2007.
It won't have support for the ribbon, forms regions or other new stuff but
it will just work.

Are you following the deployment walkthroughs for VSTO applications, using
that documentation I've never had a VSTO Outlook 2003 addin try to install
Outlook 2003 or the Outlook 2003 PIA's on an Outlook 2007 machine. You
wouldn't want that anyway, last registered wins in those cases so that would
make the Outlook 2007 PIA unavailable for that machine.

Is the Outlook 2007 PIA installed on that problem machine? If it is the code
should just install and run.

--
Ken Slovak
[MVP - Outlook]
http://www.slovaktech.com
Author: Professional Programming Outlook 2007
Reminder Manager, Extended Reminders, Attachment Options
http://www.slovaktech.com/products.htm


"lokesh" wrote in message
...
Hi,

Have created and deployed successfully, an outlook vsto addin for 2003.
But
i am unable to install it on office 2007 for one of the machines as, it is
unable to install O2003PIA as it also requires office sp2. Whenever i try
to
install offce sp2 it says product version not found. Is it because of the
registry problem since i do see the files and folders for 2003 on the
system.
Is there something i am missing.