Are you saying you installed Mach3 on your computer's C drive, or are you trying to run it from the CD? Did you get an XML file with this CD that's specific to your router? That tells the computer what pins of its parallel port to use to communicate with it; if you don't have the XML file, you have to find out what the "pin-out" is for your machine, and enter those numbers in the appropriate places, and save that profile under a special name. If your computer doesn't have a parallel port, you need another piece of hardware that will adapt your USB or ethernet port to handle communications to the router, if that wasn't included with your machine package.