C:\ProgramData\Autodesk\C3D 2015\enu\Assemblies\
C:\Users\[user name]\Documents\Autodesk
C:\Civil 3D Projects
C:\Civil 3D Project Templates
C:\ProgramData\Autodesk\C3D 2015\enu\Data\
C:\Users\[user name]\AppData\Local\Autodesk\C3D 2015\enu\Template\
If this folder does not already exist, create it at the following location to save the tutorial drawings as you work on them:
C:\Users\[user name]\My Documents\Autodesk
C:\Program Files\Autodesk\AutoCAD 2015\C3D\Help\Civil Tutorials\Drawings
C:\Program Files\Autodesk\AutoCAD 2015\C3D\Help\Civil Tutorials