If Windows is still running then it should only be the Mac i-OS operating system that's gone BUT here's what i'd do to be 100% safe with my data... If you (or a friend) has a SATA Drive enclosure, test your drive first on another computer. Most drive manufacturers have free diagnostic software for these situations, ie Western Digital or Seatools by Seagate (i'd recommend Seatools, it works with any brand of drive). Always be careful about static electricity here though especially with your hard drive and it's priceless data!!! I have successfully recovered data from a damaged drive many times with a free program called Recuva by Piriform. If the drive is fine then your Mac i-OS needs re-installed which is where you have to make a tough desicion. Risk losing everything performing a back-up or simply buy a replacement drive and re-install everything with your recovery discs then "COPY" all your data from your old drive. Good Luck, panshaker_ross@msn.com