Blend micro is not recognized USB


I have the Blend micro , I manage to download a sketch (BLE controller) once and now when I plug it to the PC (win 8.1) it says that the USB device is not recognized.
I’m not ablke to set the serial port in the Arduino IDE and not to download sketch


Could you please uninstall and reinstall the driver:


I have this same problem. I have reinstalled the drive with no change. If I reset the Blend I see an Arduino leonardo bootloader device briefly in ports then it disappears, causing a device manager refresh, followed by the USB device not recognized message. Do I need to reload the Blend bootloader? If this is required, how do I proceed?