Did a Windows 7 reinstall and one of my 3 other data drives lost its mind and can't remember that its a NTFS drive - and W7 wants to reformat it. Its been a few years, how can I recover the partition?
Do you have backups? If yes just reformat the drive. Data recovery is not 100% certain. If you want to go the way of recovery, two rules of thumb:
1) Under no circumstances perform any operations on the drive to be recovered. Do not use it, period.
2) You need to have a second empty hard drive where you save the recovered data to, you can't recover to the same drive.
I have had good success with R-studio NTFS in the past. It costs a few bucks but it's worth it.
http://www.r-studio.com/Another tool that may help you is Spinrite of Gibson research corporation. After you do data recovery, this tool may return your drive back in operation if it appears damaged. But use it only _after_ data recovery attempts.
https://www.grc.com/sr/spinrite.htm some user testimonials report that spinrite was able to fix their damaged drives back to operation even with data intact.