Hi, I've imported a movie onto Windows Movie Maker and it's playing the audio
and the screen is black. I've disabled the video filters and the problem
persists. I find this odd, because before, Movie Maker played this same clip
with no trouble. Suddenly it is. The clip is .avi, so I'm not certain why
there is a problem.
Thank you.

I've had a similar problem, except that my clips turn bright green. Just like yours, I still have audio and such.
While trying to find a solution, my roommate discovered that my color setting were too low. She pushed them up to max, and the problem with the green screen went away. (funny that it was such a simple solution, because all the techs I talked to kept telling me ridiculous things like "install some new drivers" or "reset your system".)
I don't know if this will work for you, but it's worth a try, right?