After you upgrade a computer or device to Windows 10, certain Garmin wearable devices may not work as expected when they're connected to a USB port.
Although the Garmin device shows up in Device Manager and is displayed as a connected drive in File Explorer, it is not accessible. Attempts to access the drive trigger errors such as the following:
This issue is documented by Garmin at Device is not detected in Windows 10 after updating to the Anniversary update.
To download the latest Garmin Express tool, go to Garmin Express.