WD hard drive can be seen in device manager but cannot be accessible

[s_pisces]

I have a Western Digital 500GB external hard disk. It suddenly stopped getting recognized in "My Computer" to access any data. I can see the hard disk lighted up and hear it running but cannot access it.

I tried to go to Disk Management, it shows Disk 1 Not initialized, unallocated.

Is there a way to retrieve the data? There is lot important information that I don't want to loose

 

[s_pisces]

Screen shots for better understanding

Image_1 for disk management- http://tinypic.com/r/29qmvr6/5
Image_2 - http://i43.tinypic.com/kb9n6b.png
Image_3 - http://i39.tinypic.com/2mg49yf.png

 

[kenrivers]

You might want to take a look at this thread: http://www.tomshardware.com/forum/289757-32-recover-files-unallocated-space-preserve-file-names
and this one http://www.tomshardware.com/forum/283604-32-recovery-unallocated-partition and this one http://www.tomshardware.com/forum/251070-32-help-unallocated-space-recovery
I hope something in one of those helps.