I've successfully used Knoppix (a Linux live CD) to recover data from drives that Windows (and even BIOS) claimed did not exist. It's worth a shot before trying

I've successfully used Knoppix (a Linux live CD) to recover data from drives that Windows (and even BIOS) claimed did not exist. It's worth a shot before trying other services. If lucky, your drive will be mounted after Knoppix starts and you can copy the files off to a safer spot. Good luck!