That looks like a HW install problem, not all external HDs are plug and play. If you don't have an install disk, go to mfg. website and download drivers, then install and re-boot with drive on ! Given the error, always disconnect from "Safely Remove Hardware" first before pushing the off button.
Actually, this is a plug and play external HD. I've used it before. Its just that the USB was not working /recognizing anything plugged there, and the hardware person checked and found somecable loose and fixed it. This is a front USB, and not the rear one which is built in . I tried connecting the HD to the rear USB port, and the problem was the same.