Wallpap1 will automatically update your wallpaper using the images.

This program sits in your system tray area and allows you to choose a directory of images you want to use as wallpapers, and Wallpap1 will automatically update your wallpaper using the images in the directory you specify and at the cycle/interval you specify. It supports GIF, JPG, and BMP. You can also set it to minimize/start on start-up, stretch/Tile/etc, and rotate them randomly.You can right-click on the Tray Icon for the basic options.