Hey guys! So I've had a HP Pavilion Notebook 15 for the past 5 years and had recently performed a clean erase and install of Windows 10. So after the install the following keys on the keypad stopped working:
On the numpad above the keyboard: 1-4 and 7-0
On the numpad to the right, keys 1 and 4 ( even when numlock is ON )
The right and down arrow keys.
So after searching the internet for all sorts of solutions, I've found one at this link
https/support.microsoft.com/en-in/help/927824/windows-may-not-use-the-correct-keyboard-layout-when-you-connect-a-usb
So the problem was that the keyboard layout that is set by Windows and the actual layout of the keyboard hardware, were set to be different and this caused the keys to be mapped to wrong values.
In the above link there are solutions given for various kinds of keyboard hardware currently installed on your PC. To identify which solution to follow, you can identify your keyboard layout by going through the following steps:
1. Windows + R, to open up the Run module
2. Type in msinfo and press Enter
3. In the Components tab, under Input, select Keyboard.
4. Your type of keyboard would be mentioned under Description
Using that as your reference, follow the steps mentioned in the above link, and after a computer restart, all your keys should start working properly.
Cheers!