How to make applications full screen?

[Windows Central Question]

How do I make applications fullscreen without the window bar at the top? It's kind of annoying. Also, is there some sort of setting to make applications stretch to fit when I full screen? On some of my older applications (mostly old computer games, etc.) the application full screens, but only in its original aspect ratio, filling the rest of the screen with black and not stretching to fit. And they still have the window bar at the top. =.='