How to: Set multiple startup projects
Visual Studio allows you to specify how more than one project is run when you start the debugger.
To set multiple startup projects
In Solution Explorer, select the solution (the top node).
Choose the solution node's context (right-click) menu and then choose Properties. The Solution Property Pages dialog box appears.
Expand the Common Properties node, and choose Startup Project.
Choose the Multiple Startup Projects option and set the appropriate actions.