theclarets1969 :
its my external hd i meant ? wats unreadible sorry
Sorry, I don't understand this question.
As I said, if it shows up in disk management and has a drive letter, you can run chkdsk. If it shows up in disk management but has no drive letter, right click on it and see if you can assign one. If you can it may become readable, or at least should show up in windows explorer where you can run chkdsk. If none of these work, you probably have to reformat. Drives can be come corrupted by disconnecting them while data is still being written to them.
If you have really important data on the drive, you can try running a data recovery program like
Recuva or
Pandora Recovery, and you MAY be able to recover some of your files.