I just got unbelievably lucky with an HGST laptop drive that failed. The computer crashed and would not restart. It gave me an unreadable drive error, but I was able to put it in an external enclosure and use recovery software to save an image. I then wrote the image to a new identical drive that I purchased through Amazon Prime. I had to use a Windows 7 system repair disc to get Windows 7 to start. After that I ran standard and a few other 3rd party diagnostics for error checking and repairs. I have been able to start all of the programs that I normally use without any difficulty and have not been able to find any bad data files.
I ran diagnostics on the failing drive, but it could not pass the SMART tests. I actually tried to reinstall an operating system from factory install DVDs just to see if it would do it, but it failed after a few minutes. Then I realized that the drive still had about a month left on its warranty. I have now received a replacement hard drive. it is the first hard drive that I have ever had which failed before the warranty had expired. In the past it has always been slightly after the warranty ran out.