Background Picture on Monitor

How can you "lock-in" an image as your background picture on the monitor. I know how to get the picture there from the "personalize" tab, but for some ungodly reason, I lose the image after a few minutes. This never occurred before.

Thanks!

Is there anyone on this site who can try to answer this question for me. Much obliged.

Try this:

In control panel go to ease of access center
At the bottom, choose "Make it easier to focus on tasks"
Under "Reading" see if "Remove background images" box is checked.
If it is, uncheck it and that should get your desktop wallpaper back.