April 4, and part of the celebration includes new limited-edition wallpapers created by Microsoft designers and creators.

The photo you see above -- the default wallpaper for Windows XP -- is probably the most recognizable image in the world. What you probably didn't know is that it's a real photo, called Bliss ...

Finally, if you want something a little more retro, you can grab one of these Windows wallpapers through the ages (and yes, ...