If you would like to span the main Windows taskbar across all monitors, instead of adding additional taskbars you will need to look at your Windows display configuration. The only way to do this is to have your desktop spanned across your monitors, not extended. This isn't an ideal setup though, as there is no longer a monitor divider, it's treated as one large monitor. The best solution (in my opinion) is to have to distinct monitors, and use DisplayFusion to add additional monitors to your extra monitors.