Once you install or set a desktop background on Windows Vista/Windows 7, you may not know the location where the image is saved. If you want to save a desktop background to another location on your hard drive, you must first search for it by using its file name. You can also use the same method to search for desktop backgrounds that come pre-installed with Windows Vista and Windows 7.
Right click your Windows Vista/Windows 7 desktop and select the option labeled "Personalization" on the dropdown menu.
Click the option labeled "Desktop Background" at the bottom of the "Personalization" window to open up a window where you can preview the wallpapers installed on your computer.
Point your mouse to the wallpaper that you want to save. A small pop-up box will show you the name of the wallpaper. For example, the default Windows 7 wallpaper is named as "img0."
Double click the "Computer" icon on the Windows Vista/Windows 7 desktop to open up the Windows Explorer window.
Double click the icon of the partition where your copy of Windows is installed and type the name of the wallpaper into the search box on the Windows Explorer window.
Right click the search result that comes up and select "Copy." Using Windows Explorer, go to another location on your hard drive. Right click and then click "Paste" to save a copy of the wallpaper.