x17 R1, both Function Keys and FN Button are not working!

Hi everyone. I have a Alienware x17 R1. I'm having issue with using my FN Button. It seems it doesn't work. FN+Esc Button also doesn't work. Tried to enter BIOS but I haven't got my F keys. Tried Advanced Start up and enter the Firmware setting but there's no such option that I can tweak it around. Also my function keys are such volume adjustments, Home, end and del buttons are not working as well. apart from those everything seems alright. Has anybody having that issue or any suggestions?