External hard drive is seen in device manager but can't use it

Hello,





I want to know about my laptop.
When I inserted an external hard drive in windows, it shows the blue light in hard drive and I checked in device manager whether it is shown or not. It can be seen in device manager but not in "My computer". When I entered "My Computer", I can't find my hard drive and auto run is also not come out. I heard the sound when I plugged it in like the way we hear when we plug USBs.