Solved Alt-F4 is taking me to "second screen" instead of closing

I am really used to using Alt-F4 to close the current application. I just bought a Toshiba C855 (windows 8, of course), and when I press Alt-F4 to close IE10 (the one I launch from the desktop, not the "app", although I'm not sure yet what the difference is), I get the "second screen" thing coming in from the right. It tells about choosing what happens to a second monitor connected to your system. I also get this screen when I press F4, so it seems like the whole F4 thing has been re-directed.

Every guide and manual I've seen so far says that Alt-F4 works to close an application, so why isn't this working that way?

Thanks in advance for any answers.

I'm not qualified as a Windows expert or anything, but as I understand it Alt-F4 closes Metro (i.e. Start Screen) apps, but not Desktop apps. To close a Desktop app, you just close its window by clicking the X in its upper right corner.

That's incorrect Dragon. Alt-F4 works in any kind of app.

dso999, it sounds like something has re-mapped your keys. Or.. are you sure you're pressing alt-F4? Many laptops have a "function" key that sits where most alt keys are.

Alt-F4 should still close Desktop apps as well, and certainly does for me. (In fact if you do Windows-D then Alt-F4, you can close Windows itself from the desktop.)

So I reckon it should work.

The behaviour you describe sounds like what a laptop Fn key plus F4 might do. Do you have a Fn key and what does Fn-F4 do?

Also I noticed this thread which talks about behaving Fn key behaviour on that laptop - is there anything in there which might be relevant:
http://www.eightforums.com/customization/14055-change-fn-keys.html

Thank you so much, DavidY. It was the FN key. I was so concentrated on "this new Windows 8, this new Windows 8" that I didn't even think of it as a machine issue. Thanks again.

Oh, and thanks to Mystere and Dragon, for the responses that lead to the final answer.

I now face the problem at hand

My situation is identical to that of dso999; I bought a new laptop running Windows 8.1
My 'ALT' key is behaving as my 'FN' key should. Alt+F4 is opening the screen options, as FN+F4 should have otherwise. However, FN does NOT behave as the ALT key should. FN+F4 does nothing (side note: FN+F3 opens the search bar in Chrome).

Please help, and thank you in advance.