For information, your screen resolution is 1680 x 1050 pixels
If you have a PC :
choose the photo resolution that matches your screen resolution, click on the corresponding link and then right-click on the enlarged image and choose "Set as Desktop Background" from the menu.
If you have a Mac : choose the photo resolution that matches your screen resolution and click on the corresponding link. You have two options:
Ctrl + right-click, select "Use Image as Desktop Picture" and confirm.
Save the image ("File" then "Save as"), then in "System Preferences" select "Desktop and Screen Saver" -> "Desktop" and choose the wallpaper that you have just saved onto your machine. Your wallpaper will now be saved on your Mac desktop.