HDD is a 500 GB WD Black; repair shop did in-depth diagnostic and the physical drive checks out OK; cannot access the drive from new installation of Windows 7 on an SSD or from Windows 8 Consumer's Preview.
Data is not an issue as I use Carbonite on-line data backup. Went into disk management in Windows 7 to format the drive - error that the drive cannot be formatted. So, I went searching for answers in a several forums. While there might BE some answers on how to convert from RAW to NTFS, I have only found answers that are 4+ years old and I'm hesitant to use them on this system.
Thanks, Wyoming. Yup, went back in yesterday and deleted the partition. Reinitialized and am up and running using it as a data drive. I wouldn't even have had to use it as a paperweight since it has a 5 year warranty and there are 2 years left on it.
This was all a good excuse to put Windows 7 on the SSD I got a while ago. Running the Windows 8 Consumers Preview on another drive, so life is good!
I would have NEVER trusted it, except that the computer repair shop where my son works put it on "Frankenstein," their diagnostic hardware overnight and it checked out perfect. Even given that though, if I didn't use Carbonite, like you I'd still be a little leery of it.