Gee, on my Vista machine I followed the instructions enclosed and the driver installed just fine.
In case your cable is missing the instructions (tongue in cheek sarcasim), you should insert the CD into the CD drive before you do anything else. Then plug the cable in. When the Vista driver install window appears, selected the recommended option of let windows find the driver.
Thats all there is too it. There is no setup.exe file to run.
The drivers on my RS CD are way outdated. On it the FTDI driver Version is 2.00.00 dated 5/19/2006.
The drivers on RS site are even older.
Most scanner programming software such as WINxxx etc. advise that the latest drivers be used.
Right now the latest FTDI version is 2.4.16.0 dated 2/17/2009
The “setup executeable” link I posted above will download the latest FTDI drivers and running the downloaded exe file will automatically uninstall any old drivers and install the latest. (No tongue in cheek sarcasm implied or intended)