Got a USB cable for my X600 (same cable as E700 etc).

When I connect the cable to the pc, it installs it straight away as an unknown USB device. When I try and update the driver with the one on the cd, it doesn't want to know - it just gives me the message "The specified location does not contain information about your hardware".

What am I doing wrong? It just won't install. I've been struggling with this for days, PLEASE HELP SOMEBODY!!!