I clicked on what I thought was Windows wallpaper but it was Bing, I don't know how it got in there. Then it took over my wallpaper and put on Bing wallpaper, changing pictures often. I did not know how to stop it so I deleted the wallpaper. Now when I leave the office and come back there is a black screen with a message saying it can't find the wallpaper. I can just touch the keyboard and my wallpaper shows up. Any suggestions as to how to stop the error message? I have W 7.

I found instructions for unchecking something in Bing Desktop, but I don't have that.