VSDC Free Video Editor
There is a bit of a learning curve, and it is a little complicated, however, it is free. The Videosoft dev website offers helpful instructions, such as removing backgrounds for green screening. (See link at end of article).
The program allows you to edit video files and create videos of all types. It supports the most popular video/audio formats and codecs, including DVD and HD videos. Preconfigured profiles make the creation of videos for various multimedia and mobile devices a snap. Apart from this, the program comes with a disk burning tool that enables you to burn the files you created to CD or DVD disks.
The video editor offers a number of useful features, such as audio, video and image filters, color correction and scene transition effects. You can also transform objects in your videos.
You can also use it to remove green screen backgrounds. See the instructions below.