Oh yesterday night I also have this problem. It didn't either fall or get damaged physically,  but it stopped to work. Vista hangs on after inserting the drive. Device Manager shows the device correctly but nor disk management no Explorer shows it. It's unavailable. Just after plugging out it comes for a second on the Hard Drive section (in My computer) and it gives a message : You need to format before try use it. But I can't access to it. I tried also Windows Xp, again the same result. It founds as hardware and installs requiered driver for device. Also Windows don't Shutdown or Start if the device is plugged in. Command prompting also hangs silently. Is there any way to make it to work? at least to copy data to PC???

Hi
Please connect your hdd and go to disk management right click on my computer on the desktop g to manage and iskmanagement ..
check your hard disk is listed there or no if yes check it have drive letter if no please right click and add drive leter.if its there then check it has a format like it writng ntfs or fat32 if there then rigt click on the left hand side pan and say reactivate if still dosent work may be u need to format it. or use a third party software like hard disk regenerator or mac disk worior...
THANKSAND REGARDS