Hi all, 

When connecting the board and running the Zadig program, some Windows PCs may return "driver installation failed." I coudn't find the solution from their download website. So I started the drscl first. Apparently it shows: Successfully scanned, but no boards found. Therefore I checked the Device Manager. A breakdown warning triangle appears under the serial port...

The possible solution may be found here.

Infact, the WinUsb driver has been in existence in your PC. One can just follow the instructions here: 

https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/winusb-installation 

1. Plug in your device to the host system.
2. Open Device Manager and locate the device.
3. Right-click the device and select Update driver software... from the context menu.
4. In the wizard, select Browse my computer for driver software.
5. Select Let me pick from a list of device drivers on my computer.
6. From the list of device classes, select Universal Serial Bus devices.
7. The wizard displays WinUsb Device. Select it to load the driver.

In the wizard, somehow the default setting displays Microsoft Device on the Top of the list and replaced the WinUsb Device. You can easily re-load the WinUsb Device. Just ignore the WARNING from the device manager. The board should work fine now. 

Willy