How to show the taskbar on only one display in Windows 10
Changing this setting really comes down to your own personal preferences as there are clearly some good reasons to keep the taskbar on both monitors.
For example, since the Anniversary Update the taskbar clock is displayed on both monitors. If you play games or are watching a movie this gives you an easy way to keep an eye on the current time.
Nevertheless, some people prefer the cleaner look of having the taskbar on a single display. In Windows 10, this is really easy to set up, but first you must make sure you have the right display chosen as your main monitor because once you’ve made this change it will only show up on your primary display.
So if you have a multi-monitor set up Go to Start > Settings > System > Display. Here you will see your two monitors labelled 1 and 2. Click on the monitor you wish to use as your main display and then check the box labelled ‘Make this my main display.
Now go to Settings > Personalization > Taskbar and scroll down to the Multiple displays heading. Switch off the slider labelled ‘Show taskbar on all displays’ Your taskbar will now only appear on your main display.