I just hit the PRINT SCREEN button. It copies whatever is on the screen at that moment and then you can go into Word or whatever and crop it.
So like if youre watching a movie, and you want to freeze-fram or screencap a part, hit the PRINT SCREEN/SYSRQ button (next to F12) and then pause the video (sometimes you may have to pause at the part you wanna screencap and THEN hit PRINT SCREEN) and copy and paste it into word and crop/edit away!
