As already mentioned NCH Screen (http://www.nchsoftware.com/screen/) can be used to broadcast the contents of the computer screen live over the internet. This same free software can be used to capture the screen and audio output to a video file.

Case I

A PowerPoint slideshow is made privately by the presenter, including a comprehensive commentary through a microphone connected to the computer. The presentation is captured as video and audio then edited to tidy up the commentary. The video file including the audio is then rendered for inclusion on a CD or DVD as part of a training pack. Those learning from the CD can play the video file of the presentation along with the audio commentary.