[Locked] External HDD Problem

Hi all,
I have a Western Digital My Passport External HDD (500gb) and one day, it stopped working.
When a new device is connected with USB, PCs make that beeping sound (from the speaker). When I plug my External HDD in, it does make that beeping sound, but there's no pop-up saying if I want to open it using folders, using Microsoft Fax, and other options.

So I'm guessing it is recognized by the computer, but the computer is unable to get information of what device is plugged in.
I don't think there's anything wrong with the computers itself because I've tried on 3 different laptops and 2 different computers.
So... any ideas on how to fix this?

I had a good 300gb worth of Movies, Clips, Music, Pictures and Documents in this. T^T

Edit: I've checked the device manager and it shows that my HDD is plugged in and "ready to be used".

Though it says it is ready to be used, I do not see the auto-run pop-up, and it is not plugged into one of the "Removable Disk)

- Have you tried checking your filesystems? Sometimes autorun will not work properly
A. If you can find it there, there's a probability it might be corrupted or marked as unallocated. In which case you could either shell out for a disk recovery program, or wipe the drive.
B. If not, it's likely your drive is dead, or some form of corrupted. You could look for drive recovery options, which are ridiculously expensive, or get a new drive.

What do you mean check the filesystem and how do I do that? :S

PS: OS = Windows XP

Start -> Run -> explorer.exe

Alternatively, use Disk Management.
Start -> Run -> compmgmt.exe -> Disk Management
http://support.microsoft.com/kb/309000