I own a dell 7577 with Windows 10 Home operating system. I connected a dell keyboard (KB216) to my laptop. Now, whenever I want to turn my Number Pad I have to turn it on from the num lock key on my external keyboard. The Num Lock key on my laptop does not work any more. Even after I have unplugged my external keyboard, the Num lock key on my laptop does not work; to turn it on I need to either connect my external keyboard or use On-screen keyboard to turn Number pad on. This had happened before when I had connected a Zebronics external keyboard before the dell(KB216) one. When I connected the dell keyboard for the first time it was working fine. But now all of a sudden this issue has reappeared. Guys do anyone have any idea why does this happen?