Jose When you connect your cable to the PC without connected to the radio, do you see any Prolific as a COM port in your device manager? If so what is the COM number? If it show a Prolific com in Device manager then then USB end with electronic is working. Next Power up the Radio and plus the 2 prongs end into the radio. Then open the CPS 2.1.11 (V9.1.142) then click Comm and you should have the COMx Profilic in the Com window then Read your radio. If with the proper COM port in the comm windows you cant read the radio them the cable is defective at the 2 prongs end. You can also try any cheap Baofeng UV5R like cable as it is the same. I have 2 radios and one cable and i use my Baofeng for the second radio. Hope this help
but you have not respond to the Mandatory question we got only half of the answer. Please read it and respond accordingly is you want help. We cant troubleshoot if we dont know your environnement.
Need your Firmware version as it is shown on the radio, and other usefull information, see this message link below for instruction