Adding and Removing Projects
A solution can contain multiple projects which can be opened, closed, and saved together. For example, a solution might contain a Web project and a project for a component used on an HTML page. Each project within a solution can contain multiple files or items; the types of items contained within a project vary according to the language engine.
Information about the projects and items that make up a solution is contained in a project file. The file extension for the project file differs based on the type of project and the language engine used to create it.
To add a project to a solution
Select Add Project from the File menu.
Select an existing project or a new project template from the Add Project dialog box.
Make sure that Add to current solution is checked and click Open.
The selected project will appear as a new node in the Project Explorer.
To remove a project from a solution
Select the project in the Project Explorer.
Choose Remove Project from the File menu.
The project will be removed from the current solution; it will not be deleted however, and can still be used in other solutions.