[itsme]

'notification bar' is the bar at the top of the screen. On my tablet it shows the time and a number of icons showing if WLAN or Bluetooth is active, battary status, new mails... Tablets from other manufacturers or other Android versions might be be slightlly different.'Navigation bar' means the bar at the bottom of the screen that contains the 'home' and the 'back' button. Both bars are provided by the Android system and are outside the MS window. This is why the settings are located under 'System'.
Could it be the case that you mixed it up with some MS navigation elements?