Sometimes you would want to enable or disable taskbar on extended second monitor. In my case I connected a second monitor to my laptop to be used as an extended monitor. After extending my desktop to the second monitor the Taskbar was shown on both monitors, so the monitor is extended but the Taskbar is duplicated.
How to Enable or Disable Taskbar on Extended Second Monitor:
Right Click on the Taskbar and select PROPERTIES.
Under the TASKBAR tab, uncheck the SHOW TASKBAR ON ALL DISPLAYS to disable the taskbar to be duplicated on your extended second monitor or check the option to enable the Taskbar on all monitors.
And that is it! Easy enough to enable or disable taskbar on extended second monitor.
You can also choose how you want the TASKBAR BUTTONS to be shown by changing the options under SHOW TASKBAR BUTTONS ON.