its really easy, press CTRL and look for a button saying PRINT SCREEN and it says SYSRQ underneath it, press the 2 at the same time, make sure you have all your windows closed and are looking at your desktop.
The image has now been copied, goto any image-editing program, MSPaint works fine. Then Paste it, and you'll see your desktop. Then Save the image, upload it, then link it here.
Not too hard at all.
Changed my desktop, again with an image supplied by Zanku. Damn Ein is too cute.
Enjoy