Re: f4-key doesn't work in mann versus machine.
Since you mentioned a laptop, I assume it has a "function" button (Fn).
Sometimes you need to push that button and then one you plan to use simultaneously in order to get the alternate functions on your keyboard, and sometimes, the alternate functions are preset, and you have to press that button and the button you want to use simultaneously, so you get the "normal" function.
Anyways, try that. If it's not that, I'm all out of ideas.