A couple of more to try (I prefer Ultramon that Zepher linked too), Version Comparison | DisplayFusion MultiMonitor TaskBar
For whatever reason Microsoft hasn't added the ability to have the taskbar on more than the primary monitor when using extended mode.
I had hoped to have icons and taskbar on both but that wont work unless I have them both at the low res which is unacceptable.
Unless you're looking to have identical monitors (clone mode) then you need one of the above to get a taskbar on each monitor. Icons on the other hand are as easy as just placing the ones you want on each monitor.