Question 1

“Install Driver” fails or is greyed out?

Accepted Answer

Run Zadig as administrator, close any app using the USB device, and enable Options > List All Devices to select the correct interface. If Windows blocks the install, verify the driver package is signed; only disable driver signature enforcement temporarily if you trust it.

Question 2

Device not detected?

Accepted Answer

Try a direct rear USB 2.0 port instead of a hub, use a data-capable cable, and confirm the device is in the mode that exposes the target interface. Composite devices may need the specific interface selected, not the parent device.

Question 3

Version/conflict with existing driver?

Accepted Answer

In Device Manager, uninstall the old OEM/WinUSB/libusbK driver and tick “Delete the driver software,” reboot, then reinstall with Zadig. Do not replace HID keyboard/mouse or system-critical drivers.

Zadig Driver