Some users of the D2XX drivers with our default VID and PID (0x0403 and 0x6001) have been experiencing problems installing under Windows XP. This is due to Windows XP Update trying to automatically install XP certified VCP drivers in place of the D2XX drivers.
This problem can be overcome by temporarily disconnecting form the Internet while installing FTDI devices. If the problem persists, please contact FTDI Support for assistance.