CamStudio is a free software program designed for recording what's on the desktop. There's no digital watermark unlike commercial programs such as HyperCam and Camtasia Studio and it's free.It can be used for tutorials or to record video game sessions.
Various options can be changed. The audio can be recorded from speakers, from the microphone or no audio recorded at all. Sometimes the audio doesn't keep up with the recording when playing games, so some users import the movie into movie making programs such as Windows Movie Maker and add background music. This method can be used to make the file size smaller and just edit the unwanted bits out of the movie.