Magnify your desktop and draw on it.

ZoomIt v3.03
ZoomIt is a free download tools on Microsoft technet.
I don’t know what lisence it rely on but is should be free to use on your own desktop or giving presentation to others.
It has three main features, zoom in, a color pen to draw or type text, a timer. The first two features are fun and useful enough for you to download it and give it a try.