In data recovery scenarios like this you don't work on the last good copy. You clone the drive and try recovery software titles (link to follow) on the clone. If you work on the clone you may damage it further.
Try titles from http://www.cnet.com/forums/discussions/lost-and-found-or-the-storage-forum-sticky-354911/
Hey, my brother tried to install windows 7 and formatted the drive in the process. We had valuable information there so im trying to recover it. I tried mounting Parted Magic in a USB drive, and when i boot it doesnt detect my hard drive, only the USB drive. But if i go into the hardware detector app before the boot it does. Is there something i can do?
Thanks

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