Getting Pictures That Cannot Be Copy/Pasted

I have been asked before "How can I get a picture that I see on the screen but can't copy?" The only solution I have come up with is using the Print Scrn button. All keyboard have a Print Scrn button which can be used to copy anything on your screen and placing it on the "internal" clipboard. The Print Scrn button will copy everything on the screen.

These are the steps I would use.
(1) Have the picture you want on the screen
(2) Push the Print Scrn button (saves copy to clipboard)
(3) Open up Paint (this is the program I use)
(4) Go to Edit and Paste (or CTRL + V)
(5) Use Select to box in the part you want (since you get everything)
(6) Go to Edit and Copy (or CTRL + C)
(7) Paste the picture where you want it or go to File and New and Paste so you can save the picture by itself

And you are done