Well, my Seagate Barracuda 500GB suffered a power failure. It is detected at POST and even GRUB loads off it. But after I select an OS, it's partition isn't detected. When I select linux, the kernel is successfully loaded from it's partition (so that partition is found) but it gives me a kernel panic saying that the root partition wasn't found. As for Windows 7, GRUB just shows a message saying the partition couldn't be found.
On booting into Win7 on another hard disk, the partitions of the hard disk in question aren't present.
And after that when I restart, the hard disk isn't even detected at POST. It is again detected only when I unplug the power from the motherboard, plug it back in and then switch on.
So, I am hoping that the data can be somehow salvaged. I don't care about the hard disk. I just care about the data.