src - https://lifeinhex.com/recovering-data-from-faulty-hdd/
ddrescue - Data recovery tool (linux)
https://www.gnu.org/software/ddrescue/
ddrescue - fill-mode switch
https://www.gnu.org/software/ddrescue/manual/ddrescue_manual.html#Fill-mode
OSFMount - Mount ddrescue image (windows)
http://www.osforensics.com/tools/mount-disk-images.html
Personally, when I plug an external HDD and not even appears to My Computer and appears to My Computer > Manage, Im using the freeware
Abstradrome.Repartition Bad Drive v1.01.
articles talking with the best words for Abstradrome.HDD Regenerator (paid)
also there is DRevitalize
ddrescue - Data recovery tool (linux)
https://www.gnu.org/software/ddrescue/
ddrescue - fill-mode switch
https://www.gnu.org/software/ddrescue/manual/ddrescue_manual.html#Fill-mode
OSFMount - Mount ddrescue image (windows)
http://www.osforensics.com/tools/mount-disk-images.html
Personally, when I plug an external HDD and not even appears to My Computer and appears to My Computer > Manage, Im using the freeware
Abstradrome.Repartition Bad Drive v1.01.
articles talking with the best words for Abstradrome.HDD Regenerator (paid)
also there is DRevitalize