Windows 10 Technical Preview Build 9926 (with Cortana)

Windows 10 (codenamed Threshold) is an upcoming personal computer operating system developed by Microsoft as part of the Windows NT family of operating systems. First presented in April 2014 at the Build Conference, it is scheduled to be released in 2015, and is currently in public beta testing. During its first year of availability, upgrades to Windows 10 will be offered at no charge for consumer users of Windows 7 and Windows 8.1.

The overlying goal of Windows 10 is to actualize Microsoft’s ongoing efforts to unify the Windows PC, Windows Phone, Windows Embedded and Xbox One product families, as well as new product categories such as the Surface Hub and HoloLens, around a common internal core and application ecosystem. Windows 10 also adjusts the user experience for different types of devices, and transitions between different interface behaviors on "convertible" laptops and tablets with keyboard docks. To improve the experience for keyboard and mouse users, Windows 10 adds a new revision of the desktop Start menu and a virtual desktop system, and it allows modern apps to run within windows on the desktop as well as in full-screen mode.

With Cortana!!!!!!