Query: When was the beta version of Windows 8 made available to the public?
Context: On February 29, 2012, Microsoft released Windows 8 Consumer Preview, the beta version of Windows 8, build 8250. Alongside other changes, the build removed the Start button from the taskbar for the first time since its debut on Windows 95; according to Windows manager Chaitanya Sareen, the Start button was removed to reflect their view that on Windows 8, the desktop was an "app" itself, and not the primary interface of the operating system.