Fn Keys not working properly in Bootcamp Windows 10

I upgraded to Windows 10 Technical Preview on my Bootcamp partition a few months ago. Just recently however, I upgraded to the full version released on July 29th. Now that I've upgraded, the Fn keys no longer work, and I cannot change the screen brightness, keyboard lights, or volume. I am running the latest version of Bootcamp on both Mac and Windows partitions, and Bootcamp is running on Windows. Does anyone know what might be causing Windows to not recognize the Fn key? I have also tried checking and unchecking the "Use all F1, F2, etc. keys as standard function keys" in Bootcamp control panel, but none of the options work. Help would be greatly appreciated! Thanks.