You can easily recover your data from this hard drive. The hard drive often gets the “not formatted error” warning due to virus attacks, improper operation, etc. In this situation, the inner data also becomes unreachable. Hence, by using a free hard drive recovery tool, you can easily recover all your inaccessible data for free and save hard drive by re-formatting. This freeware is really effective and helped my friend restore his photos back from his inaccessible flash drive. For more information you can check the link: http://not-formatted.blogspot.com/2013/02/recover-data-... Important note: In the future, you should properly and safely operate your hard drive, such as ejecting the drive by using “Safely Remove Hardware” tool, doing regular anti-virus scan, etc.
You also should do regular data backup in case of data loss.