Computer cannot read external harddrive

A friend was transferring via USB data from her Dell Espiron laptop (Windows XP) to an external drive (WD 5000 C032). Two things happened: During the transfer, someone a) unplugged the external drive and b) dropped the hard drive on the ground.

Now, the external drive cannot be read by any computer. When I plug it into my computer (XP), the hardware wizard "detects new hardware" and sees it as a WD device. (I can right click on the new hardware icon and view its properties, chose Stop to safely unplug it, etc.). However, the drive does not show up in the Explorer tree, nor is it listed in Computer Management > Storage > Disk Management Administrator.

Also, when the drive is first plugged into the computer, I can hear it spin for about 20 seconds, and then the spinning stops.

Any suggestions on what to try?

Thanks.