Check the USB cable that you're using. USB Drives come with USB cables that have two connectors. One of the connectors have a thicker cable than the other. Make sure that you're using the thicker cable to connect it to the PC. Do you also have a separate power supply for the HDD? USB HDD initializes after the USB connection is made. Always make it a habit of connecting the Power Supply first and then the USB connector to the PC. USB HDD is very sensitive to power supply failure while in operation. I cannot go in details about how to configure the HDD for easy operation (power supply failure tolerance). If nothing happens, your USB unit, the HDD media or both may have failed.
Check the USB cable that you're using. USB Drives come with USB cables that have two connectors. One of the connectors have a thicker cable than the other. Make sure that you're using the thicker cable to connect it to the PC. Do you also have a separate power supply for the HDD? USB HDD initializes after the USB connection is made. Always make it a habit of connecting the Power Supply first and then the USB connector to the PC. USB HDD is very sensitive to power supply failure while in operation. I cannot go in details about how to configure the HDD for easy operation (power supply failure tolerance). If nothing happens, your USB unit, the HDD media or both may have failed.