This is just... too damn cool for words...
A small internet phenomenon on Futaba Channel, the OS-tan (OS for Operating System, and -tan as an overly cute Japanese honorific for a person) or simply OS Girls are the personification of several OSes, most famously Windows, by various amateur Japanese artists. A pure fan creation, the appearance of each character is generally consistent among artists. OSes are always portrayed as women, the Windows girls usually as sisters, despite sometimes seeming the same age (or younger).
/collapses and dies