How to Create and Manage a project in Windows Movie Maker
The project keeps all work in the video or slideshow. You can save the project to complete the work later, or if you need to edit something after completion, you can resume the work. When you start working on the video, a new project is automatically created.
To create a new project, click the “FILE” button on the top menu first.
Choose “New Project” here.
And select the video ratio you want.
Now you can see that the preview window shows you the appropriate ratio.