Is it possible to change what the windows button on the screen of HP Stream does?

Question

I'm not talking about the windows key on the keyboard, it's the little windows icon/button on the screen of the convertible laptops (mine is an HP stream but I think other brands have the same button). So when you have the keyboard sitting in your lap, and fold the screen straight back, it's on the bottom in the middle, like the home button of a tablet. When you press it, though, it does have the same function as the windows key, bringing up the metro start screen. I'd like to change it to take a screenshot or something. Really just anything other than metro, because I never use it.

I've looked on google for ages, but I don't even really know what the button is called, so I could be overlooking it.

I'm fairly certain it's not possible through computer settings so does anyone know of a third party app that will let me change it? I was thinking maybe it would be possible through AutoHotKeys, but I can't find anything about it, so maybe not.

I've been trying to figure this out forever, any help would be greatly appreciated. Even if you don't know how to change the function, if you at least know what the button is called, please let me know!

I don't know if it matters but I'm running windows 8.1 (yeah, I know, it sucks, haha)