Have you tried to edit the files in another folder, and then move again, or in the same folder where they are (C:\Windows\System32\DriverStore\FileRepository) ?
Yes. Even as Administrator, from the command prompt, the action was denied. GUI spawned from Administrator had same issues.
I think what is lost in the above posts is that I removed the new version of the FTDI driver by using the device manager. Then I installed an older version of the FTDI driver that does not check for the fake chip. After that, all of the details are how to alias the drivers into allowing the PID_0000 to be successfully utilized. The Live DVD Linux disk is what allowed me to edit and save the changes for adding the PID_0000. Under the latest Windows 8.1 with current patches, I was able to edit, but not save. I was able to copy the files, edit and save, but was not allowed by the OS to move them back into the system folder.
Roger is correct from the stand point that moving the FTDI to another PC that does not have the edited drivers will not work because the Plug&Play will not happen correctly since PID_0000 will have no matching driver. Also, if the FTDI utility (or other utility) is utilized to rewrite the PID, the converter will be bricked if plugged back into a Windows machine with newest FTDI drivers.
Perhaps the very newest drivers do not change the PID but send a user message about a counterfeit device, I have read that. But whatever I installed that updated the FTDI driver and bricked the faux chip obviously was the first attempt by FTDI to trash the USB device chip with the PID_0000. I cannot speak to this newest version as I have tried to be diligent and keep the old drivers in place. The driver update was strictly accidental.