JAB

Hello, I'm new. So new that I just downloaded version 4.0.5 of Paint.net I would like to edit my NEF files from my Nikon Digital Camera, but I cannot see how to import these files. I did go to the Plugins under File Types and chose both RAW Camera Images and Digital Camera Raw Images. Still I cannot choose the files that are in NEF format. Can anyone tell me what I should be doing to accomplish the editing of my NEF files? I am not very techy!!! Many Thanks