Hey, so as the title says, I'm wondering if in Windows Movie Maker, or another free video editing program, if I can somehow place a black bar over part of the video for a few seconds. Or a blur or something.

I can get the entire screen to go black, but I really just need to cover up a few numbers before I show my video to anybody. preferably without losing audio, but if I have to, that'd be fine. I'd also be completely satisfied if I had to do it frame-by-frame. Any help is appreciated