Why isn't my published VB10 project installing the .net 4.0 prerequisite?

I have a personal project written in VB10, and am publishing it from VS2010. However, when users attempt to run the created setup.exe, they receive an error stating .net 4.0 is required. At first I assumed I had simply not set the frame开发者_如何学Gowork as a prerequisite, but I do have "Microsoft .NET Framework 4 (x86 and x64)" checked as one of the publish prerequisites.

I can't figure out why this isn't working. Am I missing some other prerequisite which the installer is calling ".net 4.0"? Am I missing some stupid "Make it work!" option box? What are the other reasons this error could appear?

Are you sure you have the "Download Prerequisites from the component vendor's web site" checked? (I'm in VS2008, so wording might be slightly different.)

It sounds as if it doesn't know where to get the install from.