so why do you have important data stored on the one device?
if its that important send it away for data recovery and dont try yourself
if its not so important theres a tool out there call hdd regenerator which *can* fix bad sectors, along with western digitals data life diagnostics or whatever its called can do it but if its that bad nothing will help - send it
There is a difference between bad and weak sectors. Weak sectors require much more time to be read; but aren't failed completely. Generally HDDs will replace weak sectors as a precaution; so many bad sectors will never get to the 'bad' state; they will be swapped before it comes to this.