Win : switch between the Start screen and the last-running Windows 8 app
    Win + C : displays the Charms: the Settings, Devices, Share and Search options
    Win + D : launches the desktop
    Win + E : launches Explorer
    Win + F : opens the File Search pane
    Win + H : opens the Share pane
    Win + I : opens Settings
    Win + K : opens the Devices pane
    Win + L : locks your PC
    Win + M : minimises the current Explorer or Internet Explorer window (works in the full-screen IE, too)
    Win + O : toggles device orientation lock on and off
    Win + P : switch your display to a second display or projector
    Win + Q : open the App Search pane
    Win + R : opens the Run box
    Win + U : open the Ease of Access Centre
    Win + V : cycle through toasts (notifications)
    Win + W : search your system settings (type POWER for links to all power-related options, say)
    Win + X : displays a text menu of useful Windows tools and applets
    Win + Z : displays the right-click context menu when in a full-screen app
    Win + + : launch Magnifier and zoom in
    Win + - : zoom out
    Win + , : Aero peek at the desktop
    Win + Enter : launch Narrator
    Win + PgUp : move the current screen to the left-hand monitor
    Win + PgDn : move the current screen to the right-hand monitor
    Win + PrtSc : capture the current screen and save it to your Pictures folder
    Win + Tab : switch between running apps