Windows Movie Maker

I recently downloaded a short movie from my cell phone to my computer. However, when it saved, it was upside down. I tried opening it using available media player, but still played upside down. I installed windows move maker hoping I can edit and rotate it. The problem, when I click on the video, it does not appear on the black screen for editing in order for me to be able to rotate it. It only appears on the right side of the screen that does not allow me to edit. Please help. These are very memorable videos. thank you.