Windows Live Movie Maker is a free offering from Microsoft that offers novice and average users the ability to edit video and from there, be able to share/publish it to Facebook, YouTube, eMail, DVD and even custom resolutions. It's a basic editor with very simplified interface, and it's part of the Windows Live Essentials Suite of applications.
This offering from Microsoft hasn't been updated in some time. It still has all the same problems and issues it had in 2011. The only thing Microsoft added was the ability to export to MP4 and changed up the ribbon interface; which I don't think is a massive improvement, but oh, well.
One problem that has remained the same is the problem with Windows Movie Maker not working with certain webcams [web camera (s)]; even Microsoft's own LifeCam. This can be just about any webcam, but the point is that Windows Movie Maker sometimes just doesn't work.