Remove this bottom bar

Hello, DiD1. That bar on the bottom of the screen is a submenu bar, like right-clicking on an icon on a Windows 7 desktop. That bar is giving context, in this case for the My Computer icon that you have clilcked and probably right-clicked. If you unselect My Computer, the bar should disappear.
 
I'm not sure how you can explicitly make the switch to a traditional right-click menu. Although you're getting largely the same options.