Is DCU-65 the model of the phone or of the cable?
Just plug it in and let windows search the internet for the driver has always worked for my Sony phones.
Which is correct. It will detect several different pieces of hardware when you hook the phone up, including a bluetooth network adapter if your particular handset has bluetooth.
Strip all Sony software from your machine. Download and install the latest PC Suite. If any hardware can't find drivers, point it at the program directory. Job done.