Welcome to DPX version 4.2 for AutoCAD Civil 3D 2010, 2011 and 2012 download page.  

Required Permissions  

To perform this procedure, you must be a member of the Administrators security group.  

Installing Devotech Professional Extension

To install Devotech Professional Extension

Launch the 64-bit "Devotech PX 2012 (v4.2) (64bit) Installation.msi" file

• The DPX installation wizard appears. 
• On the Welcome page, click Next. 
• On the Devotech PX 4.2 (64bit) Installation Information, click next.
• On the License Terms page, read the terms of the license. Click I Agree, and then click Next. 
• On the confirmation page, click Next. 
• Click Close to finish.
• Launch AutoCAD Civil 3D
• In the command line, type "CUILOAD"
• Browse to the following folder: "c:\Program Files\Devotech\DPX20XX\Support", and select "Devotech_Pro_Ext_2012.cuix", and click open.
• Click Load, and then Close
• You will see the DPX ribbons loaded.