This damn project

so in my art class, I have this film assignment. We're supposed to take clips from a movie, record ourselves discussing the clips, then edit them all together. Since I'm one of the only ones in my group who has any experience with film editting (it's one of the only artistic things I'm good at), I'm the one in charge of putting the film together. So here's what's pissing me off about it: I can't convert the film into a format that either windows movie maker or imovie can read. If I can't do that, then I can't trim it into clips.

When I first received the burned copy of the dvd, my pc would play it, but when i tried to save it on my pc, it saved them in a way that wmm could read it. I talked to my brother, who's an IT, and he recommended a program called handbrake. Now, handbrake was able to convert the files into an mpeg4. My copy of wmm can't read that. I figure, itunes can read mpeg4, i bet imovie can too. So I go to my school's mac lab, and it turns out that imovie can't. I still don't understand why. The people there recommend I try to convert it to avi. So, I look online and find a program that converts mpeg4s to avi. It finds the movie file and converts it to avi. I know that wmm reads avi, so I try to use it again. It now recognizes that the movie is there, however it won't import it because it says that the file is corrupted. I'm pretty sure it's because the avi file includes the menus and wmm doesn't know what they are. I'm getting really frustrated with all of this.