Hey there valentine21,
I am really sorry that you are having issues with your My Book Essential. Could you provide some more info on whether you see the drive in Device Manager and Disk Management?
As volcanoscout already suggested, you can try it on a different USB port and on a different computer. Using a different USB cable is a good idea too.
If this does not help and the device is detected in Disk Management, check whether it has a letter assigned. If not, you can assign one. (link below)
Have you done any software updates recently? You can try reinstalling the drivers of the device. You can do this the following way: Device Manager -> find the USB device -> Uninstall -> turn off the hard drive. After that you can turn it on and...