Random BackGround can chnage your desktop's background, it allows you to select a folder of bitmap images which will be used to select an image to be set as the desktop wallpaper.

This application can be set to run on startup, every certain amount of time, or a combination of the two. Random BackGround currently supports BMP, DIB, JPG, and GIF image types.

The license of this software is Free, you can free download and free use this wallpaper tool software.