How Do I Import Videos From My Camera On To Windows Movie Maker?

Every time I try using videos I’ve uploaded on to my computer on Windows Movie Maker, it won’t let me import it. I upload the video from my camera on to my computer and save it in the “My Videos” folder. Then, when I select “Import Videos” on Movie Maker, the file doesn’t show up. I have a Nikon Coolpix camera and a Dell laptop. Anyone know how to fix this problem?