Does keyboard work in bios? See if you can change boot device to USB and get into safe mode or even see if advanced startup recognises keyboard and/or works normal
On another PC, download the
Windows 10 media creation tool and use it to make a win 10 installer on USB
change boot order so USB is first, hdd second
boot from installer
on screen after languages, choose repair this pc, not install.
choose troubleshoot
choose advanced
choose start up options
hit the restart button
choose a safe mode (it doesn't matter which) by using number associated with it.
PC will restart and load safe mode
if you can get this far, and keyboard worked enough to let you login, its clearly a driver issue or one of your start up programs causing it.
try word pad and confirm keys work.
try resetting keyboard settings -
http://www.thewindowsclub.com/reset-keyboard-settings-default-windows (while in safe mode)