If you need to recover data from a crashed external hard drive check out this article which covers both, logical as well as mechanical disk failures. Here you find valuable tips & tricks for recovering data residing primarily on external disks, but the information is also useful for internal disks.

• Introduction

  When an external hard disk crashes your next step depends on whether the disk is still working mechanically. If you are “lucky” the disk works, but it has lost the index of the data on it.
  To find out attach the external hard disk to your computer and make sure the disk gets power if it has its own power device. If your computer recognizes the disk but does not show data (e.g. disk not formatted) do NOT format it and continue with section Software Data Recovery.
  If, on the other hand, the external hard disk does not seem to get powered attach the disk internally in your computer. If the disk is recognized chances are high you see all your data intact, and all you have to do is dash to your computer hardware retailer to buy a new cage or power supply. If the disk is dead read on in section Lab Data Recovery.

• Software Data Recovery

  In case of logical failures, such as when Master File Table (MFT) in Windows has been corrupted your data is still there but the index to it is missing. The first important step is that you stop writing data to the disk.
  Now you need you another hard drive with the same capacity as the crashed disk, or bigger, plus specialized recovery software such as GetDataBack, ParetoLogic Data Recovery Pro or EasyRecovery (Standard Edition). Alternatively you can try the free excellent tool featured in Bright Hub’s article Recuva – Top Free Recovery Tool: Undelete Files.
  
  

  • If you’re not satisfied with Recuva’s results then use the paid software, or perhaps even better consider outsourcing the data recovery process to an IT professional in your neighborhood as this may reduce total costs for this incident.
    Depending on disk size the data recovery process can take days during which the recovering computer should not be turned off. Chances are good that you will get your data back, or at least a large part. If the index (MFT) cannot be reconstructed you will get your data in the form of individual files without the folder structure.

  • Lab Data Recovery

    In case your external disk does not spin or work mechanically you should not try to fix it yourself. Never open the hard disk unless you are absolutely sure about what you are doing. Instead get in contact with a specialized lab like Ontrack Data Recovery Services or google the web for a similar company with a track record.

  • The Bottom Line

    Try to prevent data recovery actions and costs by safely removing external disks and making regular backups - very large disks have become incredibly cheap. You can simply use another external disk for you backup as it is very unlikely that both the primary disk as well as the backup drive fail at the same time.