A free software (there is a paid option as well) that can screen capture your desktop image and create videos for presentations. This software is limited depending on the version of operating system that you have.
"Capture video files on your Mac or PC with this easy video recorder software. Debut is designed to be very easy and intuitive to use, giving you the ability to record essentially anything from capturing video from a webcam, your screen, or video input devices such as a VHS recorder within minutes of downloading."