how do i put pptx into windows movie maker?

hi im trying to put a powerpoint presentation into windows movie maker but i dont really know how. i tried importing it and dragging it in but both times i got the message “The file F:\Modern Art A-Z.pptx cannot be imported because the codec required to play the file is not installed on your computer. If you have already tried to download and install the codec, close and restart Windows Movie Maker, and then try to import the file again." i have absolutely no clue what that means. Help please!