When I first installed Windows 7 beta, I was surprised to see the default wallpaper which was a FISH, which of course I myself or most of us didn’t expect. It turns out to be that there is a valid reason why Microsoft had this picture of a fish as the default wallpaper. In Windows Vista Microsoft used photographs which were taken by their employees and added as wallpapers.
Coming back to Windows 7, this particular fish which is called Siamese fighting fish is one of the most popular fresh water fish. The fish is also known as BETTA FISH After reading the following article about Siamese fighting fish, I realized why Microsoft came up with the picture of this fish.
http://en.wikipedia.org/wiki/Siamese_fighting_fish
According to Microsoft this wallpaper will be the default wallpaper only on the beta and will be changed in the future builds and releasesof Windows 7.