Windows 8 will support all Windows 7 applications and older Windows 7 hardware. It uses a smaller footprint (less memory, fewer processes), even on older hardware. But no mention was made of backward compatibility for older Win32 apps, like those built for XP. Windows 8 will include Hyper-V in the client and that will, presumably, be the method whereby an enterprise will run its legacy apps.

Windows 8 starts fast and shuts down fast. The team demonstrated boot times that were less than a few seconds. "W8 boots almost faster than a monitor can turn on," Sinofsky said.

Windows 8 will ship with a range of security software including encryption such as Bit Locker and a firewall. Sinofsky said Microsoft has beefed up its integrated anti-malware software, Defender, as well.

Applications will be tightly integrated with one another, and to system level services so that a user will have access to application context-aware functions within the application menus, such as the volume button when watching video.

Pop-up controls, called "Charms," will offer cross-application functionality. Clipboard, for instance, has become the Share Charm and this not only allows users to share text and graphics between applications, but to post clipped data to social networks, among other functions. Application developers will have access to Charms to easily add functionality to their apps.