The current version of the FTDI driver depends on which version of Windows you have.
There are links to all of them on this webpage http://pscan.uk/install/windows.html
The other problem is there are some customers who are still on the old pscan.eu software. The upgrade sometimes works and well and sometimes doesn't. The solution is to create a new empty folder c:\pscan.uk and start again with the software from here http://pscan.uk/install/install.html