Within IE if I rightclick on a video, I can download a video from you tube. That facility non existent within firefox. How do I enable downloading?
Youtube does not usually offer users an option to download their videos. Chances are you have a plugin installed (possibly accidentally) in your IE, thus allowing you to do this.
You can download Youtube videos by installing addons such as Ant.com Video Downloader to Firefox.
Try Video Download Helper extension for Firefox:
Home page: http://www.downloadhelper.net/