The Autodesk Civil 3D Object Enabler is installed when you install Autodesk Civil 3D and it is also available from Autodesk Account.
The Autodesk Civil 3D Object Enabler is automatically installed when you install Autodesk Civil 3D. It is uninstalled when you uninstall Civil 3D.
In addition, you can also download the most current version of the Autodesk Civil 3D Object Enabler from Autodesk Account. For more information, see How To Download Object Enablers for AutoCAD.