just as a test to see if this works at all so that i can find out more details about the problem. save a random picture from the internet, may i recommend this one (
http://www.mamaroneckbeachandyacht.c...landscape1.jpg)
Note to Moderator: I have no affiliation with the above site, simply a great picture.
Right anyway back to the topic, go to the link above or select one of your own, and open it up in Paint or another graphic editor and then set it as your desktop wallpaper. Then let me know whether it works or not.
If the new image is not displayed, or even if it is but you can only see part of it and the rest of the screen is white then I think I already know what the problem is, due to active displays.
You have also forgotten to provide a very important piece of information, which version of Windows are you running, whether that be Windows XP (home, premium) Vista (basic, home, premium, etc)