Displays the Add Project dialog box so that you can add a new or existing project to the currently open project group. If you have only one project open, Visual Basic adds the project and creates a project group. A project group exists only if there is more than one project.
Note If you do not have a project group opened, Visual Basic automatically creates a project group containing the existing open project and the project you add.
A project group can contain any number of other projects. It is an easy way to load more than one project at a time
The first EXE project you add to your project group is automatically set as Startup unless you change it using the Set as Start Up command on the Project Explorer shortcut menu.
When you add an in-process project to the project group and reference it, the project appears in the References dialog box and is stored in the project file.
When you add a project to a group, Visual Basic checks if any of the other projects in the group have a reference to the binary version of the newly added group. If they do, the references automatically are changed to the source version.