How to remove FTDI's cached registry entries in Windows 7

Question

I have an FTDI USB-to-comm-port device. I've noticed if I have to reprogram the device using FTProg that it doesn't properly reinstall the COM port driver/settings, if the device serial number stays the same.

When I have the device installed (I chose mysernum as a serial number), the registry keys look like this:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\DeviceClasses\{4d36e978-e325-11ce-bfc1-08002be10318}\##?#FTDIBUS#VID_0403+PID_6010+mysernumA#0000#{4d36e978-e325-11ce-bfc1-08002be10318}
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\DeviceClasses\{4d36e978-e325-11ce-bfc1-08002be10318}\##?#FTDIBUS#VID_0403+PID_6010+mysernumB#0000#{4d36e978-e325-11ce-bfc1-08002be10318}
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\DeviceClasses\{86e0d1e0-8089-11d0-9ce4-08003e301f73}\##?#FTDIBUS#VID_0403+PID_6010+mysernumA#0000#{86e0d1e0-8089-11d0-9ce4-08003e301f73}
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\DeviceClasses\{86e0d1e0-8089-11d0-9ce4-08003e301f73}\##?#FTDIBUS#VID_0403+PID_6010+mysernumB#0000#{86e0d1e0-8089-11d0-9ce4-08003e301f73}
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Enum\FTDIBUS\VID_0403+PID_6010+mysernumA
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Enum\FTDIBUS\VID_0403+PID_6010+mysernumB
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\FTSER2K\Enum
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\Serenum\Enum
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\usbccgp\Enum
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\FTSER2K\Enum
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Serenum\Enum
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\usbccgp\Enum

If I uninstall the comm ports using Device Manager, there's still stuff left in the registry, and if I rescan devices in Device Manager, it skips some of the installation steps and pulls the COM port setup from a cache somewhere. The remaining registry keys are

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\DeviceClasses\{a5dcbf10-6530-11d2-901f-00c04fb951ed}\##?#USB#VID_0403&PID_6010#mysernum#{a5dcbf10-6530-11d2-901f-00c04fb951ed}
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Enum\USB\VID_0403&PID_6010\mysernum
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\services\usbccgp\Enum
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\DeviceClasses\{a5dcbf10-6530-11d2-901f-00c04fb951ed}\##?#USB#VID_0403&PID_6010#mysernum#{a5dcbf10-6530-11d2-901f-00c04fb951ed}
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\USB\VID_0403&PID_6010\mysernum
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\usbccgp\Enum

I need to purge the cache for a particular device serial number, but I don't feel comfortable doing brain surgery in RegEdit.

How can I do this?

score 2 · Answer 1 · answered Jun 09 '16 at 21:41

I figured it out. This is a dual serial port converter (FT2232H) so in the Device Manager it has one entry per port under Ports (COM & LPT) but also a USB Composite Device under Universal Serial Bus controller. I was uninstalling the two ports but not the USB Composite Device.

This is easier to find in the "Devices by connection" view of the Device Manager:

If I uninstall the USB Composite Device, it cleans up all registry items completely, and allows a clean reinstall.

Cody · Answer 2 · 2016-06-09T21:46:37.877

0

If the registry key isn't used at all I recommend using registry cleaner software (eg. ccleaner)

If you want to go all tweaky on it I recommend this tool for "ghost" devices removal:

http://www.uwe-sieber.de/misc_tools_e.html

3rd solution should be enabling "hidden devices" in Windows's Device Manager and remove+delete driver tick

edited Jun 09 '16 at 21:46

answered Jun 09 '16 at 21:41

Cody

21
2

device wasn't hidden, it was just obscure (how the heck was I supposed to know to look for a USB Composite Device?) – Jason S Jun 09 '16 at 22:00

How to remove FTDI's cached registry entries in Windows 7

2 Answers2