I am using Office 2003 and VB .NET 2003.

MSFT KB article 302896 includes a step by step example demonstrating how to
build a COM add-in using VB .NET.
The example works with Access, Excel, Outlook, Powerpoint and Word.

For Excel, the add-in works as advertised.
However, using the add-in's uninstall project does not uninstall the add-in
from Excel.
Note that VB .NET add-ins cannot be listed in the Office COM Add-ins menu.

How does one remove a VB .NET add-in from Excel?
--
http://www.standards.com/; See Howard Kaikow's web site.