You can also use Windows Live Photo Gallery to create your desktop wallpaper for Windows Vista. To install Windows Live Photo Gallery, navigate to the Windows Live website and download Windows Live Essentials. You can install this software if you're running either the 32 bit or 64 bit version of Windows Vista Basic, Home Premium, Business or Ultimate. After installation, type "Windows Live Photo Gallery" in the search box and select the entry under "Programs." On the right, you will notice that Windows Live Photo Gallery has many of the same tools as Windows Photo Gallery. It also has additional tools, such as "Straighten photo," "Adjust Detail," and "Black and White Effects." You can also adjust shadows and highlights in the "Adjust Exposure" tool.
When you've finished creating your desktop wallpaper, set it as your desktop background by clicking "Control Panel," "Appearance and Personalization" and "Change Desktop Background." Browse to the location of your new wallpaper image, then select the image. At the bottom of the screen, select how the wallpaper should be positioned. In most cases, "Fit to Screen" will be your best bet. Then click "OK."
To find more choices for your Windows Vista desktop wallpaper, read Make Your Desktop Come Alive With Windows Vista Wallpaper.