My FN key does not work or activate any of the Function keys. How can I fix this?

I'm using a Lenovo desktop computer running windows 8.1. I just recently bought a new keyboard to replace my broken one, and now whenever I hit the FN key and try to use my function keys it doesn't work. None of the commands seem to do anything. This is particularly annoying because I have a back lit keyboard, and part of the adjusting of said lighting is utilized with the FN key. I contacted the seller and he has no idea how to fix it. The keyboard is and AULA gaming keyboard. My computer is a Lenovo 10104 Version 6.3.9600 Build 9600. It is 64 bit. Hopefully that is enough information for the tech savvy people on this website to help me. I'd appreciate any help at this point, as Google searching my issue only brings up other issues with the function keys that have nothing to do with mine.

Desktops don't use the FN key. In fact I only know of laptops, that even have a Fn key.