I thanks for your comment nihil.

As this thread is too old, but if you permit, I would also like to share my experince with data recovery case..

As it is clear from my above statement that I have lost data in past. Due to software malfuntion.. Was on the verge of loosing my data. But while researching on the net for data recovery software. I came to know about Stellar Phoenix FAT & NTFS data recovery software. Indeed a good software. I don't know how many have used this product. But it acted as a life saving drugs for me. To get back my data, I simply download the demo version to test the software how it works. http://www.stellarinfo.com/partition-recovery.htm
Demo scan the hard drive, showed the information in tree tructure form so that navigation through file is easier. Recovered data was show as marked 'deleted'.
The best point is that we can save the scan result from the demo version, after getting the full version there is no need to start the scan again. All we have to do is to save the data.

I find it really perfect and become the fan of Stellar Phoenix Product.

I would highly recommend to those who have lost the data can try this product.