Using default Windows driver for USB CDC devices

Posted by Vladislav Nikonov on 12 September 2020


Recently I have moved from Linux to Windows OS as my daily driver and I needed to connect to my PocketCHIP via its built-in USB CDC mode. But I am instantly stumbled upon the issue: even this USB-to-serial is a pretty normal USB CDC class device, Windows was not able to install drivers automatically.

Usually, device vendors provide their own signed device drivers, but it is usually a big pain in the backside to find the special driver for each CDC device. So I was almost ready for a whole lot of pain during the driver search, but then I thought - "Hey, it is 2020 already, maybe Windows could offer something simpler?"

How about usbser.sys?

It is turned out that Windows already has a default USB-to-serial driver starting form Windows 8.1 - usbser.sys, which is just needed to be selected manually for the device, as Windows does not select it automatically! So, here instruction how to use it (WARNING: I am not liable for any damage to your hardware/OS, you are doing this on your own risk!):

  1. Select the device in the device manager, press the right button and then press "Update driver" First step image

  2. Press "Browse my computer for driver software" Second step image

  3. Select "Let me pick from a list of available drivers on my computer" Third step image

  4. Search for "Ports (COM & LPT) in the list and select it Fourth step image

  5. Select "Microsoft" in the left list and "USB Serial Device" in the right list Fifth step image

  6. Press "Yes" on the appeared warning Sixth step image

  7. You are ready to rock!