Just as an FYI, and I I am sure you have tried this sequence but I will post it anyways. This is how I have always done it:
1. Plug the USB cable from your Phantom (port under the rubber flap) to your computer.
2. Run the PC Assistant.
3. Click skip, then login, or whatever until you get to the main screen.
4. Power on your Phantom.
5. If that doesn't get it connected, I wouldn't know what to do either.
RC Assistant, same general thing. Except run the RC Assistant and power up the RC.
Good god I would hate my life if this all didn't work for me. Good luck and I hope you get it working.