Choosing a Theme:
There is always a series of default themes present in Windows 8 - which are ready-made packages of special background images, screen-savers and sound effects. These ready-made themes contain one theme that is based on flowers and one around the Earth. You can pick your desired theme from available themes by right-clicking on the empty space on the desktop, choosing "Personalize" and then selecting one of the Themes available in your Windows. All pre-available themes contain a selection of images and the desktop background will keep changing as it cycles through those images. If you want to manually move onto the next image then just right-click on the desktop and select "Next Desktop Background" from the options menu.