WallShow is a freeware application which helps you change the desktop wallpaper automatically with any user intervention, you can specify the time interval after desktop background should change, It gets minimized in your system tray after it starts running. We have covered similar application before like High Resolution Automatic Wallpaper Changer and Automatic Desktop Wallpaper Changer
Note: It supports BMP, GIF, JPEG, DIB, and PNG if Active Desktop is enabled and BMP if it’s disabled.
Once you run this program you will first need to specify folder containing images.
This folder of images which you have specified will be used to select the images to set as desktop background.