Here is the solution.
In most cases the problem is in MBR (Master Boot Record) created in your drive's MBR sector by OS you had before upgrade or patch with service pack etc. So, basically what we need to do to get our HDD back to life is to write the MBR signature (the Hex Word 0xAA55) to your drive's MBR sector.
It is easy to do.
1. Download this utiility:
http://www.cgsecurity.org/wiki/TestDisk_Download
2. UNzip it somewhere on your computer then find and run "testdisk_win.exe"
Here is what you will see on your screen when running Test disk:
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TestDisk 6.2-WIP, Data Recovery Utility, November 2005
Christophe GRENIER <grenier@cgsecurity.org>
http://www.cgsecurity.org
Select a media (use Arrow keys, then press ENTER):
Disk /dev/hdc - 708 MB / 675 MiB
Disk /dev/sda - 120 GB / 111 GiB
Disk /dev/sdb - 120 GB / 111 GiB
( in the liness above you will see YOUR hard drives), so select the one which you have problem with, then press "ENTER")
[Proceed ] [ Quit ]
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Next step is to select the partition table type
You will see on your screen something like:
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Disk /dev/sda - 120 GB / 111 GiB
Please select the partition table type, press ENTER when done.
[ Intel ] Intel/PC partition
[ Mac ] Apple partition map
[ None ] Non partioned media
[ Sun ] Sun Solaris partition
[ XBox ] XBox partition
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So, select [ Intel ] and press enter
Next screen:
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Disk /dev/sda - 120 GB / 111 GiB
[ Analyze ] Analyze current partition structure and search for lost partitions
[ Advanced ] Filesystem utils
[ Geometry ] Change disk geometry
[ Options ] modify options
[ MBR code ] ......
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You need to Select "Analyze" then press enter
New screen will appear with something like:
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Disk /dev/sda - 120 GB / 111 GiB
Current partition structure:
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1 * FAT32 blah blah blah............
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You don`t need to change anything , Just press ENTER
New screen appear which will look almost the same, the only difference that on the bottom you will find result of the disk structure test. If your disk is not damaged ( in most cases it is will not be find as damaged. it is just misconfigured) so just press "ENTER" to proceed to the last step.
NOTE: If your drive found as damaged you can recover it using the same utility ( how to do this? see docs on authors site)
Now we are almost done!
After you pressed "Enter" in previous step you will see something like:
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Disk /dev/sda - 120 GB / 111 GiB
1 * FAT32 0 10 blah blah bla.......
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And on the bottom:
[ Quite ] [Search] {Write]
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We need to select [ WRITE] option. Use right arrow on your keyboard , select [WRITE] then press ENTER.
DOne!
NOW the very last step:
disconncet your external drive from your PC and plug it in again
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That`s it!
I am sure now you are saying YEEEEESSS!!!!!
Your drive now appears in MyComputer .