Windows XP was the most blissful iteration ... After all, it's arguably most famous for its signature "Bliss" wallpaper depicting a rolling green hill, deep blue sky and little fluffy clouds.

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 ...

According to Instagram account Inside History, the Windows XP wallpaper image was taken in 1996 by photographer Charles O’Rear. It was acquired by Microsoft some time between then and the 2001 ...