A year or two ago, I took a Matlab training class and the presenter had some kind of tool that let him zoom in on a portion of his desktop so that we could read his code, as well as draw on his desktop using his mouse, for example circling the a window he wanted to draw our attention to. The zoom/draw tool worked really well (we all asked what tool it was) but I can't remember now. It was a Windows machine, if that helps. Any idea what this tool could be?
In Windows, there is a built-in tool call Magnifier.
You can change the setting to
There is also a commercial tool called Magnifying Glass Pro which has more options.