Some points to note about the new un-installation method:
In the case of FT2232/FT4232 devices, a composite device is also installed. This can
also be removed by right-clicking and selecting "Uninstall". There is no option to
delete the driver files when doing this as the driver for the composite device is a
native Windows driver. If the VCP driver has been installed, the COM port driver
should be uninstalled before the USB driver. If the bus is removed first, the COM
port will no longer appear in the Device Manager.
If the files are deleted while other installed devices still require them those devices
will not work correctly. This can be fixed by right clicking the device and selecting
"Reinstall Driver" which will replace the missing files. If a device to be uninstalled is
not connected to the PC, the device can still be removed by setting the device
manager to show phantom devices. This also allows a virtual COM port to be
uninstalled if the bus layer has been removed first.
Troubleshooting
Windows 7 cannot find drivers for your device
This error can occur if the VID and PID programmed into the device EEPROM do not
match those listed in the INF files for the driver. The VID and PID programmed into
the device EEPROM may be found by using the USB View utility from the FTDI web
site. These can then be checked against the VID and PID entries in the driver INF files.
If they do not match, that driver cannot be installed for that device without either
re-programming the device EEPROM or modifying the list of VID and PID numbers in
the INF files.
Devices not shown in Device Manager for uninstalling
Devices that have been installed on a system but are not currently available are
referred to as "phantom devices". These devices are not usually displayed in the
device manager, but can be made to be displayed as though they are attached. This
allows device properties to be changed or devices to be uninstalled via Device
Manger even though the device is not physically connected to the PC.