Update.
A ram check has not been run. Reason, I thought about it and at no time have I seen erratic behavior. It is exactly the same every time. A photo gets put on the desktop and slid to the right until only a third is showing. The rogue photo is over the wallpaper photo and under the icons.
More observations
My screensaver is a slide show. That works fine, as before.
Under control panel/display
I pull down the themes tab and I see a change. It should be set for Windows Classic, but now reads Windows Classic (Modified). Allows me to select Windows Classic again, but doesn't fix the problem.
When I right click on the desktop, click arrange items by, and then unlock web items on desktop, this seems to activate the rogue picture. One time I was able to grab the picture by the top bar and move it on the screen. It appears to be a desktop sized window with a photo. It then froze in new position, can't be moved, clicking the x doesn't exit it.
So, problem has appearance of a bogus desktop. Hmmm, must be a web items folder somewhere.
stay tuned