Step Three Pick out the edition you want of Old Windows Betas. Select your edition Windows 7 Beta 1 build 7000 Windows 8 Milestone 1 build 7850 Windows 8 Developer Preview build 8102 Windows 8 Pre-Consumer Preview Preview build 8128 Windows 8 Consumer Preview build 8250 Windows 8 Release Preview build 8400 Windows 8.1 Preview build 9341 Windows 10 Technical Preview build 9926