Windows 7 build 6471

A screenshot of Windows 7 build 6471 was found on TCB. This image comes from the Microsoft MIX09 conference, where this build was briefly shown during the "Evolution of the Windows 7 User Experience" segment, as well as the leaked build 6519 (probably by coincidence), an unknown build between 6519 and 6801 (where the build tag is hard to read due to the Windows Vista default wallpaper), 6801, and 7000. There are also three earlier images, dated April, May, and July 2007, which may be real builds, although no buildtag is present.

The MIX09 conference is located here: https://www.youtube.com/watch?v=2BpEspjE8Ik. The relevant sections begin at 25:27.