I think the combination of "FN + Print Screen" works for most laptops with Windows system. But if this way does not take effect, you may try the Snipping tool which can be accessed from "Start" - "Accessories" - "Snipping". It comes with every Windows system and provides quick workaround for making screenshots. This solution does not rely on any third-party program, but the only drawback seems to be that it lacks of editing options for polishing your image. You may try a free online screenshot tool to overcome this issue.