pepin, tried all that, to the letter, early on. Even did a complete system restore and then cleaned the registry. Connected when requested, same error. To be honest no drivers were installed, so there is nothing to uninstall apart from minor registry entries from the beginning of the installation.
Using non pro driver (in fact, they are the same but still using non pro driver selection).
Installing as administrator is not the issue. I have UAC and suchlike turned off anyway.
The installer runs until right after the controller is connected (and I tried using USB 2.0 and USB 3.0 ports) which it detects and allows me to click next, then it immediately gives an error.