The Startup Project options makes it possible for you to specify which project or projects run when you start the Visual Studio debugger. To open the Solution Property Pages dialog box, select your solution in Solution Explorer and choose Set Startup Projects on the Project menu. Under Common Properties, select Startup Project to display this page.
Single startup project
Select this option if you want just one project to run when you start the debugger.
Multiple startup projects
Select this option if you want to specify how more than one project is run when you start the debugger. After selecting multiple startup projects, you can control the action of the Start command on the Debug menu for individual projects using the Action column.
If you use the option for multiple projects to run, then you must select Build Solution on the Build menu to build the startup projects.
Displays the projects currently loaded in the solution.
Specifies which option is selected for a project. Click in the cell in this column to select an option from a drop-down list.
Run the project when you start the debugger
Start without debugging
Run the project when you start the debugger, but do not debug this project.
Do not run this project when you start the debugger.
Changes the order of selected project in the list causing it to start before another project when the debugger starts.
Changes the order of selected project in the list causing it to start after another project when the debugger starts.