To use on Windows
Select the size image that best corresponds to your screen's resolution, then once the image has fully loaded, right-click on the image. A pull-down menu window will appear and select Set As Wallpaper or Set As Background. Your selected image should now appear as your dekstop wallpaper.
To use on a Mac
Save the image size the best corresponds to your screen's resolution to your hard drive. Click on the Desktop to make the Finder active. Select Preferences under the Finder menu. Change the wallpaper by pressing the Select Picture button.
Your screen's resolution is
.