Sure.  Just get the picture you want displaying as full-screen as you
can make it, then press the "Print Scrn" key on your keyboard.  This
will copy the picture to the clipboard.

Then enter any image editing software (even Paint ;-) and Edit>Paste
to get the clipboard image into your editor.  Then save the image as,
say, a .jpg file in My Pictures.

Then right-click on your desktop and select Properties, click on the
"Desktop" tab, and use the Browse button to navigate to your image
and select it as your new desktop image.

-michael

Home page:  http://members.aol.com/MJMahon/

"The wastebasket is our most important design
tool--and it's seriously underused."