• We recently switched our forum platform. If you experience any issues please email support@crystalfontz.com

Completely remove CFA635-USB


New member

What are the steps to COMPLETELY remove a CFA635-USB from an XP system? If I uninstall the COM port and the USB controller in device manager and plug the device back in, it still installs the stored drivers on the system. I want to completely remove all drivers, registry settings, files, etc from the system so when I plug the device back in, XP prompts for device installation and I can then point the Windows driver installation wizard to the driver folder to then do a complete re-install of the driver.

What I would like is a driver removal utility like other manufactures have that can be ran.

My problem: I have a display that won't be detected on the COM port it emulates. If I plug a completely separate display into the USB port, windows installs from stored drivers and the display works. If I take the display that doesn't work on this system to another system, Windows installs and it works. It's like it's tripping over some configuration in this Windows installation. Also if it's a fresh install the display works.

Looking for additional LCD resources? Check out our LCD blog for the latest developments in LCD technology.

CF Support2

1) Go to device manager uninstall (remove) any Crystalfontz devices

2) From Add/Remove programs; Uninstall Crystalfontz USB drivers, then any FTDI Drivers, then any Crystal Control software (either version 1 or version 2)

3) Disconnect any Crystalfontz displays

4) FTDIClean Driver Removal Utility:

use Vender ID (VID) of 0403, and leave the PID blank

5) Search for "ftdi" in files named OEM*.inf in your Windows\inf\ directory. You will find at least two of them. You may need to change the folder view in order to see system files / folders. After you find the OEM files, make note of their number (ie OEM5.inf, OEM16.inf), then delete them. Then delete the corresponding OEM#.pnf files - they will have the same name, just the extension will be different.

6) Remove any Crystalfontz folders from your Program Files folder.

7) Reboot your system

That should get everything cleaned from the system for you.


New member

Thank you for the detailed instructions! The Clean utility did it. After that I plugged the display back in and it prompted for new device installation and I pointed to correct drivers and everything worked great! The display is back working on this machine.. thank you!
USB LCD Displays - Graphic and Character LCDs with a Keypad