It seems my laptop doesn't remember the power settings anymore.
Everytime I switch it ON, I can see the screen brightness has changed (against the setting I made when it was ON last time).
This happens in both modes - battery powered as well as AC Mains powered !!
How to make a permanent settings to suit my requirement (like I want to have display intensity set at 90% when on AC Mains power and at 60% when on battery mode)??