Well, if you look on your keyboard, somewhere you should see a button that says "Prnt Scrn" or "Print Screen". If you press that button, it will take a picture of your screen. It may seem like nothing happened, but it did. Now you can open up another program to paste it on. I suggest using the Paint Program. Once open, you can press CTRL V on your keyboard, and the screen picture should come up. Then, you can cut and crop the picture until it's the right size. Then you save it and use it somewhere, like on this website's photo gallery.