Visual Studio 2008 Setup Project does not include VC_redist

I know this must have been answered before, but I cannot find a reference...

Problem: How do I configure a Visual Studio setup project to include and install the VC redist package?

Info: I am creating a Visual Studio 2008 C# Win Forms project that uses native code through a managed C++ dll. In order to install this program on users computers, I made a Visual Studio Setup project. The only problem is, I cannot seem to get the x86_redist package to be included in the install, thus, the program fails to launch on users computers who do not have VS. (Yes, this is a Release build.) I have attempted adding a PreRequisite in the C# program, and I have attempted adding a Merge Module in the setup program.

Thanks for the help!

More detail:

The exact error message is this: Exception caught! System.IO.FileLoadException: Could not load file or assembly "MyInterface, Version=1.0.5354.28734, ..." or one of its dependencies. The application has failed to start because the application configuration is incorrect. Reinstalling the application may fix the problem. (Exception from HRESULT: 0x800736B1)

That HRESULT is a COM Exception, and essentially seems to wave its hands and say "Something bad happened". Any hints?