
Windows 8.1 aims to advance the Windows 8 vision, and brings support to devices sporting 7 to 10-inch screen sizes; along with smarter search, richer multi-tasking, and a more powerful and harmonious Start screen that sees the return of the Start button (though not the Start menu). The final bits of Windows 8.1 is expected by the end of this month; known as Release to Manufacturing (RTM), it will first reach the hands of PC OEMs, so that new devices loaded with Windows 8.1 can be ready by October 18. According to The Verge, Microsoft is expected to continue working on Windows 8.1 between RTM and general availability.
SOURCE:Windows blog,the Verge