Try this program.. it can repair the HDD file system, or recover your data after which you can reformat the HDD. Active Partition Recovery is a paid program and it may detect the problem and files in the HDD but it may not recover them withoug a license, I recommend it because it can easily determine if the HDD is repairable* and the files in the recoverable**, and you can use another freeware program of the type to complete the job, depending on the severy of the issue.... Google for Partition Recovery Programs.
Active Partition Recovery.
http://www.partition-recovery.com/download.html
* The boot sector or partition table may have to be repaired.
** With the right tool, files can be recovered even without repairing the issue, or even after a format.. depending again on the damage.
After file recovery is done, without a HDD repair, you can repair it with a Low Level Format Tool, a HDD wiper, or with a tool named Flobo Disk Repair which seems to do a better job in restoring HDDs.
It's also possible the HDD may have suffered permanent damage.. If the software is not able to recover files, try the HDD repair tools. If the HDD is still good it will be repaired, and if it's not, every attempt to repair and recover will fail.
Partition Recovery Programs
https://www.google.com/search?hl=es-419&source=hp&q=partition+recovery+software+free&gbv=2&oq=partition+recovery+programs&gs_l=heirloom-hp.1.2.0i19j0i22i30i19l9.27297.27297.0.34414.1.1.0.0.0.0.135.135.0j1.1.0....0...1ac..34.heirloom-hp..0.1.134.8snpoMWdUWY