My keyboard and mouse did not work on a normal boot up.
Had to off the PC. Switch the keyboard and mouse to different USB ports. On reboot, the mouse and keyboard resumed working again.
Check the internet, and realised there are many users also facing the same problem, particularly those with ASUS motherboards (same as me).
One user suggested to go to Control Panel - Power Options - Change Plan settings - Change advanced power settings - USB settings - USB selective suspend setting - Disabled.
I have try this, and switch the keyboard and mouse back to the original USB ports. So far, everything looks good. But not sure whether the problem fully resolved, or will it come back and haunt me again.