How to remove “Microsoft Windows Is Not Genuine” scam message

“Microsoft Windows Is Not Genuine” is screen locker that displays error notification claiming that you use an illegal copy of Windows. This error states that user must enter an activation key to restore system. The pop-up window also contains a link (“Click here to get your key”) that leads to a site with a survey after completing which victim will be redirected to a pay-per-download website (sharecash.org).