If affordable, if possible, boot a usb or dvd backup/restore/clone utility, one of your choosing, and clone your source HD onto an external target HD, HD would be best. Put that target HD in a safe place, in case more drastic recovery attempts are needed.
You are now at an important fork in the road.
1) DIY path -- there are numerous free and pay-for data recovery utilities and there are many threads all over The 'Net that can guide you through DR.
(Be aware -- several data recovery specialists indicate that many end-users, in the midst of their crisis, often "try everything", those who don't succeed find out from DR companies that now recovery is much harder, much less successful in general, and much more expensive.)
2) Send the HD to any well-known, well-respected DR specialist or company, and let them handle the recovery attempt.
** I'm at school, I cannot walk you through this process of making a clone or a hard-drive full image. You will have to ask a local computer guru to walk you through it. **