There are several advanced customization settings for locking down VirtualBox Manager. Locking down means removing some features that the user should not see.
VBoxManage setextradata global GUI/Customizationsproperty [,property ...]
Do not allow users to start VirtualBox Manager. Trying to do so will show a window containing a proper error message.
VM windows will not contain a menu bar.
VM windows will not contain a status bar.
To disable any of these VirtualBox Manager customizations use the following command:
$ VBoxManage setextradata global GUI/Customizations