Code 39 for USB keyboard, really odd problem/solution to share


May 19, 2011
A customer gets the update to Win10 1803, and immediately after the update the USB keyboard stops working, and no other USB keyboard works, and trying a different port didn't help. I went in expecting something malware related as malfunctioning keyloggers can cause problems like this.

Device Manager reported that for 'USB composite device', the file %hs cannot be found. In driver details, only one file is mentioned (usbccgp.sys). sfc /scannow didn't help, upperfilters for keyboards was normal, dism /restorehealth didn't help, rebooting didn't help, a quick scan with malwarebytes only turned up PUPs. Uninstalling the device and all USB bus-type stuff didn't help. Nothing interesting in the event log. Nothing interesting in usb.inf (it looked standard). While the Microsoft Keyboard & Mouse Centre was installed, uninstalling it made no difference.

I then had a thought about usb related services and whether there might be something wrong in the registry. I went into HKLM > System > CurrentControlSet > Services, down to usb and found a service corresponding to the composite device (usbccgp). In the 'ImagePath' string, all it said was "\Sy". I checked the next USB entry in the list, copied that ImagePath string, changed the file name at the end to usbccgp.sys, uninstalled the problematic device, scanned for hardware, job done.

I'm at a complete loss as to what originally caused the problem though. It would be odd for the 1803 update to even bother looking at those entries as they're near identical to Win7 let alone possibly changing between Win10 updates.

I'm also a bit surprised that a USB keyboard needs the 'USB composite device' when the USB mouse works fine. I thought the composite device was only used for devices like printers.