If you have Linux flavour OS installed and if your disk is crashed then try following steps if you want to retrive data from ddrescue commands.
Ddrescue is a program that copies data from one file or block device to another,
it is a tool to help you to save data from crashed partition. It tries to read and if it fails it will go on with the next sectors, where tools like dd will fail. If the copying process is interrupted by the user it is possible to continue at any position later. It can copy backwards.
Install dd_rescue or ddrescue