Check out the solution in this thread: [https://support.mozilla.org/questions/1041688 How do i exit fullscreen mode on a tablet PC operating Win8.1 and no physical keys?] In short: * Open the charms bar by swiping in from the right side * Tap Settings, then at the lower right, the icon to call up a virtual keyboard * If there is not an Fn key in the lower left corner of the virtual keyboard, use the keyboard selection button (lower right?) to try other available keyboards until you find one with Fn* * Tap Fn to change the number row to function keys and then tap F11 Any luck? ''*'' ''If the standard/full keyboard is not among the options, another article says you can add it as follows: ''Change PC Settings => PC and devices => Typing => Touch Keyboard => Add the standard keyboard layout as a touch keyboard option => Turn on