Hard disk crashed

When I connect My Passport Essential 320 GB hard disk to my PC, Windows (7) says that my hard disk isn’t formatted and I need to format it to be able to work on it. I looked around and have realised that this is probably due to some bad sector(s) on the disk.

Please tell me the cause and remedy to thid problem.

Thank you! 

Format it?

I don’t think it’s the sectors, since formatting is not enough to fix them. Sounds more like plain data and/or file system corruption.

So what do you suggest that I do?

Run a file systemr repair software like TestDisk first, or Recuva or PhotoRec for file data recovery if the file system can’t be fixed, then format it.