How to get rid of smartscreen on & smartscreen off

my niece has forgotten or will not say what she has done to the desktop but it displays smartscreen on and smartscreen off on the bottom of the screen with a line constantly going backwards and forwards. I have removed some programs that looked like yhey might be the culprit to no evail. I have also turned off smart dithering which did not resolve it also reverting the OS back to an earlier configuration did not work. Any help with this would be greatly appreciated.