@avadhesh
HDD writes in the same place again and again... so, as much as u use the HDD, it becomes that much Difficult to recover past data as it fades out...
Theaoritically once written on a HDD, can b recovered any time, but practically it becomes almost impossible to recover the data after 20 ot 30 times or re-write !!!!
anyway,
Basics as u said...
1st of all, the HDD it self needs to b physically OK, what I mean by OK, that Check whether BIOS of the PC is detecting the HDD or not... !!!!
Now if the Disk or Head is physically Damage, End user tools wont be able to recover data !!!!
all These software is good enough to recover or restore lost data in instances of file lost by accidental deletion or FARMAT or such... !!!!
Personally, I suggest corporate users to use Stellar Phoenix as previouslly I have seen it in action to recover files from pretty bad situations... !!! now there are many others, but i have not tried them !!! Note. this tool is a paid software !!!
Web Site do provide Demo Download which will not going to give u option to recover or perform extensive search... for those u need to have the full or activated version...
Anyway, Back 2 ur problem with asuming that u have a full Version (Let's not discuss how u get it
) ...
See, allow the Stellar Phoenix to complete the entire HDD Scan, which will bit while.. then go through its options to recover ur files... !!! as after it completes the scan, it will present a Windows Exploer like inter face with readeble data !!!