Build a PC FN key problem on Windows 8.1

Sorry if it's the wrong section.

Hi guys I have a problem with my new keyboard.
I am running Windows 8.1 and I've tried on other computer on windows 7.
The "Fn" key doesn't work. On the box it's says the keyboard comes with shorcuts like Fn+F10=Computer.
If I try a "test key program" it doesn't seem to recognize it.

Please tell me what to do.

My keyboard I think it's a no-name keybaord . "digittex" I could not find any drivers for it.
Please help.

Take a look at this pic: http://gyazo.com/027b91c04a7bb5992ec953bcc0ee8d6e.png
That is my keyboard.
(1) -> Shows that I have a "Media" button. (I also have play/pause , volume down and volume up) (All that are working)
(2) -> You can see the images of "Internet Explorer, Favorite, Search.
(3) -> The windows doesn't recongnize the "Fn" key so I cannot acces the keyboard "shorcuts"

Take a look at this pic too: http://gyazo.com/eae91a4f3d3fbf4629537787fb366e68.png
That's what it says on the box:
(1) -> You can see "FN+"
(2) & (3) -> You can see what it supposed to do.
Ex: FN+F10 = My Computer.

Help me please
.