Today, I am experiencing a terrible change in my screen viewing. Nearly all internet websites (including this one) are framed for an envelope viewing screen. If I want to read something at the edges I have to "move" the screen from side to side and there is an inch and half blank space at the bottom. Has anything happened overnight? It was not like this yesterday. I am viewing on a 16" diagnonal screen which was fine until today. I have not changed anything on my computer.