In a 3D view, click View tab
Windows panelUser Interface drop-downViewCube.
Alternatively, click 
Options. Click the ViewCube tab, deselect Show the ViewCube, and click OK.
In a 3D view, click View tabWindows panelUser Interface drop-downViewCube.
Alternatively, click Options. Click the ViewCube tab, deselect Show the ViewCube, and click OK.