select the "Set as Wallpaper" soption.
You may wish to invoke the stretch or center command in your display properties, which on a PC is accessed via a right click on the existing desktop under properties or via your control panel into display.
The best way to install desktops is via a Netscape browser, Microsoft's Internet Explorer does low quality bitmap conversions so I highly recommend a Netscape browser for quick setting of desktops.
I will be adding new desktops in the future to this page.
Regards,
Simon Mansfield
Editor
SpaceDaily
Note: The images uncredited, and are either copyright by their respective originators or are public domain. If you wish to use the images for anything other than private use I suggest you contact the obvious producers of the original images and follow their policy uses.