I'm trying to configure a multiple project solution to debug the currently selected project. I have other multiple solutions that are set this way. All the solutions, including this

Example

say to open Common Properties and select Startup Project. But that's missing from my projects, even the one that is set up correctly.

The only item that shows up under Common Properties is Framework and References in all project.

In this someone said they hacked it by editing the csproj file, but it looks like they set it to debug one particular program.

csproj edit

But they don't specify which csproj file. There are 165 in the Visual Studio 2010 directory. I am working with C++. This is happening with both WINAPI and MFC projects. I have a mix of both.