This is bit complicate stuff where I am stucked. I was struggling to make my system work properly. For that I had made changes to my bios. I had deleted a number of settings from there accidentally and landed upon many errors. My OS failed to boot. I was not aware about the settings I do not remember what I did in Boot Sequence setting of bios. I had tried to changed the completely. Now I had re-installed Windows Vista and all drivers, applications that were needed. But on boot I cannot see my D drive. That is the partition which was having full data. I had not made any changes to system partition. The C drive was by default assigned as 80GB which I am using right now. So my answer is that there is possibility of getting it back. It would be located somewhere in bootsec.bak. How can fix that stuff back.