There was a registry hack in AutoCAD that allowed you to change an installation from Standalone to Network and it worked. Then in AutoCAD 2010, it stopped working.
By popular demand, it is back but it is completely unsupported! I am posting this because the Inventor team has posted something similar in regards to this issue.
AutoCAD Family 2011
Just extrapolate the values for AutoCAD 2012. Please note that this Registry settings are very similiar for other products and may NOT work. i.e.Autodesk Simulation.
NOTE: Always backup the Registry and/or make a note of the values! It is easy to break the Registry but difficult to fix it. Hack the Planet!