I know this thread is a little bit old. But, I still want to share my opinions with you.
As I know, a hard drive is often damaged logically or mechanically.
The logically damaged drive often can be repaired after re-formatting and the contained data also could be restored with the help of data recovery program.
However, oppositely, the physically damaged drive often cannot be fixed and the stored data is also gone with the physical drive.
So, disconnect this drive to your computer and use a data recovery program to take a chance.
In order to avoid data recovery failure, you’d better not save anything else on the same drive. Anything new on the same drive could rewrite your inaccessible data and make it gone permanently.
And then, select a proper data recovery program to retrieve your inaccessible data back. I know there are some drive data recovery freeware available online, such as Recuva, TestDisk and iCare Data Recovery Free, etc.
If this really makes no difference, consulting an expert for help as soon as possible could be a really good way to go.
I suggest you give a try to the free recovery software which helps recover data from formatted hard drive I used before,it's recommendded by one of my friends , I can till remember how panic I was when I suddenly last all the data and files,fortunately,it helps me find all them back ,you can find it here , http://www.easeus.com/datarecoverywizard/recover-formatted-partition.htm .I think you can have a try ,hope it can helps you too!
If the HDD is dead and not spinning, we may try replace the exact same type HDD chip board and try to load the HDD and slave the drive to get the data back.
If there is anything wrong inside the HDD physically such as control arm or heads, we need expert to get the HDD working again.
This is going to cost money, unless the data is very important, mostly just change a new HDD is more affordable.
I think you can try Recuva if you are looking for a freeware. Expect this, all are commercialware and you need to buy them. But before getting any recovery tool, either freeware or commercialware, you must find out the reasons which cause corruption in system hard disk drive. There are many causes which can corrupt or damage your hard drive. I would like to share a blog here in which you'll read about all the possible causes behind corruption or damage in system hard drive. You'll also read how to avoid these causes to corrupt or damage our system hard drive.
Read this blog. Hope this would be helpful. Once your doubts are cleared (regarding for corruption in hard drive), you can try Recuva or any other tool. But first try to get their trial or demo version.
I also want to recommend software that can recover deleted files on the hard drive, the program named the Bitwar Data Recovery as I have used it to recover my deleted files successfully. It supports recovering data on various devices.