Hi Clive,
you were looking for a screencasting tool.
I came across ActivePresenter as screencasting tool. It's free as long as you only
output video and it's highly professional.
I used it for a couple of screencasts and it is really comfortable. You can split your
video, make certain screens appear longer, highlight and do voice recording afterwards and
during capture, as you wish.
Here is the link:
http://atomisystems.com/
Kind regards,
Thorsten