One of the biggest potential annoyances with Mavericks and a second connected display is that the OS X Menubar is available on all displays, and not just the primary one. Fortunately, Apple has included a way to turn this off, and it fixes a second annoyance.
To do this, visit System Preferences > Mission Control, and uncheck the box labeled “Displays have separate Spaces.” You may be required to log out after making this change.
So, what does this change do? Well, besides the obvious change of making each display share the Spaces instead of giving each display its own set of Spaces, this will also remove the Menubar from all displays except for the primary one. You can always change this preference back to its original settings by checking this box again.
Mac101 