So that you can service an installation (e.g., provide patches for bugs or
security vulnerabilities), you need to use a "bootstrapper" that first
installs the interop assembly .msi, then runs your VSPackage installer. MSI
has limited support for "nested installations," but there are many
limitations that make them unsuitable. See
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/msi/setup/neste
d_installation_actions.asp
for details.