anda hit the "Print Screen" button on the bahagian, atas right side of your keyboard. It's to the left of "Scroll Lock" and "Pause Break"
That is basically like right-click=copying your whole screen, so anda have to paste your screencap somewhere and save it.
MS Paint works really good for that. Then anda can do what anda like with it, like save it, sunting it, etc. atau save it and muat naik it to some other program.
Either use prntscrn button on your computer, the snipping tool if anda have Windows atau use VLC player to screencap a video (there's a really good tutorial on this somewhere in livejournal).