While there are a few steps involved, once you have practiced them, you can get it set into place in just the space of a co-worker's walk to the printer & back.
Step 1: Create a picture of the desktop & set it as the wallpaper
Once you've done that, press the "Print Screen" key. On some keyboards, it is labeled PrtScn or something similar. Pressing that puts an image of the screen in the clipboard. launch Microsoft paint, choose Edit/Paste, and you should now see an image of the entire desktop. Save the image onto the hard drive, then choose File/Set as background (Centered)