According to the description of the software, this is actually a plug-in for the AutoDesk's AutoCAD application. Also, you have to specify the Settings path for the program to work properly. Failing to do so will give you the message that you've also encountered above. Access the application's page at Software Informer to download the latest version of the software.
After you get the package, right click it and choose Run as Administrator (needed to access the system partition).