I mean, I still mostly use Windows MM for non-demanding videos. I do have Sony Vegas for anything more intensive, but yeah. If you're looking for relatively powerful free editing software, check out Lightworks or VideoPad. Lightworks is more powerful, but you can only export at 720P unless you buy the full version. VideoPad lets you do 1080P but it has slightly less features. Either would be a huge step up from Movie Maker though.