Download the newest TunerPro RT software from this link.

Plug your cable into laptop, no need for vehicle, and go to Control Panel, Device Manager, find the com port number and check driver. Should be:
Driver FTDI
Date 4/10/2012
Version 2.08.14 has been working for all. has worked for a lot. Anything higher could have issues!!! If you'd like to read up on it check this post and thread that started the diagnostics to find the issue with drivers.

Do the same for the USB Serial Converter.

Open TunerPro RT and go to Tools, Preferences, Data Acquisisition/Emulation, Choose Use Plug in, configure plug in and make sure it is on the correct Comm port, Test for Valid Interface using settings... with cable plugged in.

So with cable plugged in you found it in device manager as Com port 3, drivers are correct, TunerPro is set to Comm 3 and tests good? Don't worry it does not test good connected to vehicle.

With TunerPro open click View, Toolbars and check them all, these icons are easier to learn then all the others under like Acquisition, Tools etc...

Click Acquisition Load Definition File and choose your ADX for data looging.

Connect cable to vehicle, vehicle running, TunerPro running and Acquisition Start/Stop Data scan or click on the 2 arrows icon up top, also click on the folder icon or Acquisition Show Data Lists and data should show... this is how I do it and then click record, when you stop recording it will prompt you to save the file with a name.

Or uninstall all USB in device manager and restart, let it install what's on laptop, then first thing to plug in is cable and make sure the above drivers are installed.
*End last resort for drivers*