Windows 7 & CF634 USB - No driver installation possible


New member
Hello there,

I cannot install the CF634 USB in Windows 7 x64.
The LCD is shown as "usb <-> serial" in the device manager.
I tried every single Windows 7 driver version available from this site.
When I try to update the driver by pointing them at the source for the new
drivers it never finds the drivers. I even tried different paths etc., nothing worked
so far.

I know that the screen works, since I saw it turning on during the bootscreen.

Help would be much appreciated.
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New member
Iam having the same issue as lazykoala.
Ive tried the newest drivers ( but its not working.

Any idea pls?
USB LCD Displays - Graphic and Character LCDs with a Keypad


New member
This one is not working too. Still the same issue.
Is there a way how to test if the display is faulty? I have the display for some time now and I didnt use it.

CF Mark

Ok, can you check what the USB device hardware IDs are?

Go into the windows device manager, right-click on the "USB<->Serial" device, select properties, select the "Details" tab, then select "Hardware Ids" in the drop down box.
Taking a screen shot of the list might be easiest, or copy and past the list in here.

CF Support2

Going to jump in here and offer up some 'tribal knowledge':

We've seen from time to time over the years that every once in a while the FTDI driver installation goes sideways. We've looked into it, FTDI has looked into it, and to date there's been no detectable reason. What does work is to blow away the drivers, and then manually install. After doing this, you can connect as many displays as you want pretty much trouble-free.

What we're going to do is have you clean up the USB drivers and Crystal Control from your system, following these steps:

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) Reboot your system

7) Install the Crystalfontz USB driver from the following link:

(you may need to use Internet Explorer to get the link to work correctly)

8) Plug in modules one at a time and configure

9) Then use appropriate WinTests for each module, which you can get from here:

This should eliminate any driver issues so we can continue to trouble shoot this issue if we need to.


New member
Appreciate your help
Iam stuck with the step 7 - downloaded the last version driver from microsoft update but there is no exe file in the zip
dont know how to install it
Or can I first connect the display and then choose manual drivers instalation from downloaded zip file?

CF Support2

Sorry for the delay -- for some odd reason I wasn't notified of your update :(

At step 7, extract the files in the .zip file to a location of your choice -- for example c:\drivers\crystalfontz

Then you'll want to manually install the drivers.

Again -- my apologies for the delay in getting a back to you on this.