Download Uninstaller from here:
http://sigma-shop.com/software/ftdi/CDMUninstaller_v1.4.zip

Unconnect all FTDI devices from PC.

Run "CDMuninstallerGUI.exe"

Click on "Add" button

Click on "Remove devices" button

Connect again device to PC and install drivers

Run "HyperTerminal" and connect to Serial port

Touch in example using screw-driver between RXD and GND pins.
Green LED (RX) will blink and HyperTerminal will show randoms symbols