Hi , Thanks for the reply.
I am noticing this lagging issue since day1 of the laptop bought. I tried couple of times resetting the PC from the options (option1 with remove everything as sub option ) suggested before posting on forum. when it reset, first thing i do is open task manager and observe disk and it always reached 100 % as soon as it was on for the first time . For a change i tried loading previous version of OS today and opened task manager immediately when it turned on after reset, Screen shot is below :( :(