Using programmes like Microsoft CHKDSK and ScanDisk can result in more problems with your drive. Also, if you attempt to extract your data the progress bar may indicate that it will take several hours or days. In these cases the time is allowed for the system to make multiple attempts to read the drive which can cause it to degrade further. The best chance you have of recovering your data is if you take your drive to a data recovery specialist and allow them to examine it.
Read my data recovery blog for more information about sectors and the causes of bad sectors
John Reid, Cheadle Data Recovery, Manchester, UK.