This SVG (Scalable Vector Graphics) image is free for you do whatever you want with, set it as your computer background or wallpaper. I made it and released it into the public domain. You can find it at DeviantART and this DeviantART direct download link for the 1024x768 version of this image:
I made this page here for those who want the public domain SVG graphic. With a free SVG editor like the Adobe Illustrator Alternative, Inkscape, you can edit out the CHEXED watermark without damaging the image!