If you use a resource file in your application, you can see the RES file appear in the project window under “Related Documents.” This is the only type of file that VB automatically adds to this node of the project tree. You can add any type of file you like to this area manually, though. From the Project menu, select Add File, or right-click on the project window and select Add File from the context menu. In the dialog box, select All Files for the file type and check the Add As Related Document option.
Adding additional related files here helps organize your project and gives you quick access to useful items, including design documents, databases, resource scripts, help-project files, and so on. Once a file has been added, double-click on it in the project window to open it with the appropriate application.