Simply Windows 7 build 7077 with french mui.
However this wallpaper (apparently one of the official regional theme for France!) really has something special for me.
First, it's my town, Annecy!
But this place is exactly where I was at elementary school. On this pic taken from the bridge, you can see it on the left : [link]
I've crossed this bridge four times a day during almost ten years! That's all.
And this place looks even more beautiful under the snow: [link]