Microsoft's mysterious "Windows 8.1 RT Update 3" is no longer a giant secret. The software giant has updated its Windows 10 FAQ to reveal some more information on the future of Windows RT. While Windows RT is still effectively dead, Microsoft is planning to push a minor update in September that will bring the new Start menu and an updated lock screen. It's not clear if windowing of apps (like in Windows 10) will be available in the update, but the Start menu addition will be a welcome change for the small amount of Windows RT users.
Windows 10 includes a special tablet mode that switches between a fullscreen Start Screen and a smaller Start menu, but it's unlikely that Windows 8.1 RT Update 3 will include this type of switcher. Microsoft's approach to the Windows RT update is similar to the company's Windows Phone 7.8 update that provided a small subset of features to Windows Phone 7 users that were unable to upgrade to Windows Phone 8. Microsoft isn't providing Windows 10 to Windows RT users, so this update is the end of the line for tablets like the Surface RT. There's no exact release date for Windows 8.1 RT Update 3 other than the month of September.