Apple Wireless Keyboard - Fn key not recognized in Windows 10 (Bootcamp)

Ok, checked the input language, I have ENG (Swedish Apple Keyboard), and SWE (Swedish keyboard), no difference regardless of what I choose - That is to say, the on-screen keyboard doesn't light up for the wireless keyboard and not for built-in keyboard on the macbook, but the built-in keyboard works without problems, even with fn key.

I did however, just now, add a third keyboard: Settings>Region&Language>Languages: Press English, choose options, "Add a keyboard", chose: "ENG, US (Swedish Keyboard)". But I didn't select it as input lang/keyboard in the taskbar - Still have the ENG (Swedish Apple Keyboard) as input language. And now the Apple Wireless keybord seems to be fully functional in Windows 10. The fn key, the F-keys and the apple special keys (volume, brightness...) works.

Thanks for your guidance and help.

So when I press a key on the Apple Wireless keyboard, only the ctrl-, alt-, cmd-, shift-, tab- and similar keys gets "lit up", on the Windows on-screen keyboard. But I can still type any letter character on the wireless keyboard, and the computer will output it, in e.g. notepad.

Hi, no it's the 2009 version of the wireless keyboard, Model no. A1314

https://en.wikipedia.org/wiki/Apple_Wireless_Keyboard

Also worth mentioning is that it is of Swedish keyboard layout.

Hi, well, no the virtual keyboard doesn't respond to the fn-key, but not for any other keys except ctrl, alt, cmd (windows-key), tab, caps lock and some other...