I have an addin that was created with VS.NET 2005 and VSTOR SE.
This addin also has an install project.

The install has prerequisites of:
..Net Framework 2.0
VSTOR SE
CDO 1.21 (for machines using outlook 2007)
SQL Server Express SP2.

When installing the Addin using the setup.exe (which verifies and
installs the prerequisites), the addin installs and works properly on
CLEAN Windows XP with either Office 2003 OR Office 2007. The clean
windows XP is running in a VPC environment. "Clean" in this context
means Windows XP and Office 2003 have been installed. Office 2003 was
installed using the "custom" option, and ALL features were installed
to HD. After XP and Office 2003 were installed, Microsoft update was
run until all service packs, patches, and hot fixes for XP and Office
were installed. I have a another VPC that has clean Windows XP with
Office 2007 installed. Again, the install for the addin works as
expected for these 2 vpc's. The addin loads and functions properly.

I also have a VPC with a "Clean" Vista with Office 2003 and another
VPC with a "Clean" Vista with Office 2007.

The issue is that the install that works fine on XP does not work on
Vista.

The install completes without raising any issues. After the install
has finished installing all the pre-requisites appear to be in place.
(SQL Server SP2 is running, the cdo 1.21 files are in place, and the
VSTOR files are in place).
When Outlook is started, the addin does not load, nor is an exception
thrown. When I go to the Com AddIn dialog, it just says "The addin was
not loaded. A runtime error occurred during the loading of the com add-
in."

I have tried the following to no avail:
--Made the VPC "Clean" again (discarded undo disks), installed all the
pre-requisites by downloading their installs directly from MS and
running manually. After all were installed, instead of running
setup.exe for the addin, I ran setup.msi for the addin. The same
outcome occurred.
--Verified that the registry keys created by the install (such as the
keys to load the addin) are created in HKEY_CURRENT_USER.
--ran caspol.exe via the cmd prompt and verified that the directory
that the addin is installed to has full trust.
--Made the VPC "Clean" and installed to both "C:\Program Files\
[Project Name]" and "C:\[Project Name]" to try to avoid any
permissions issues.
--Made sure all of the dll's referenced by the addin were in place
after the install (they were)
--Tried running the install (setup.exe) AND outlook as "Administrator"
both with UAC on and off. No difference.

On a Vista Development machine (Vista, office 2007, VS.NET 2003,
VS.NET 2005, various dev tools, etc...) the addin installs and works
properly. Running the same install on a Clean Vista, causes the issue
listed above.

Does anyone know what else should be examined to try to get the
install to work in Vista?

Thank you.