This document provides an overview of the new features and capabilities of the upcoming Windows 10 operating system. It was unveiled in September 2014 and is scheduled for release in late 2015. Key additions include an updated Start menu, universal apps that can run across devices, improved multitasking features, and the Cortana digital assistant coming to the desktop. The document also outlines how to join the Windows Insider program and install the pre-release version of Windows 10.