Community
I would suggest re-posting this message over in the installation and licensing forum (at the following link). You'll likely get a better response.
Good luck!
http://forums.autodesk.com/t5/Installation-Licensing-Community/tkb-p/24_1%40tkb
Don Ireland
Engineering Design Technician
Try a "Repair of your Installation".
Go to start - control panel - programs-uninstall a program - pick AutoCAD Civil 3D and select"change" and the Autodesk dialog screen will pop up giving you the option to repair or uninstall the installation.
Bill