I haven’t heard about this being a known issue but apparently several people have experienced the same issue with Windows 10, it seems like Windows disables Num Lock at boot up. I found this thread from the Microsoft Community forum with several suppose fixes for this issue. Some users have confirmed the fixes were successful.
Dell | Alienware Technical Support
Opening your case does not void your warranty! Check out Alienware Artificial Intelligence
I can't always reply to PM's, if you need extra assistance visit: