Data recovery from damaged external hard disk

If the drive has sustained physical damage you will need to consult a data recovery expert. Please explain the problem in greater detail.

Trying to access my external hard drive The error I get is "E:\is not accessible. The file or directory is corrupted and unreadable". I took the drive out of it case and connected universal hard drive adaptor and I still get the same message. What else can I do??

How do you damage your external hard disk, dropping it or something else？ You need to provide more specific information.
Actually, a hard disk can be damaged logically or physically.
The physically damaged drive often cannot be detected by a computer, or get numerous bad sectors, or even broken, etc. It cannot be fixed and the inner data also lost.
The logically damaged drive often can be detected by a computer. But it also cannot run normally, such as receiving the "not formatted error", RAW file system issue, etc. However, fortunately, this drive still can be fixed by reformatting it and the inner data also can be recovered by using a data recovery tool.
Hence, if your drive is only logically damaged, you could try a free hard drive recovery tool from http://blog4mark.blogspot.com/2012/11/how-to-repair-cor... It is worth a shot.

Is this a free data recovery tool?