he means you don't know how to take a screenshot. And that can be done by pressing the "prnt scrn" button in the (most likely...) right upper hand corner of your keyboard. Nothing will come up on the screen, but pay no mind to that, open up MS Paint or any other photo-editing program, and hit paste, and voila.
I do not have a screen capper on my laptop, so here is just the picture I used,
