I've tried disc management, manager but still not working.. What should I do????

You left out the story, details so I'll take a leap that this is some drive you want to recover files. I'm having pretty good luck with Recuva. Try that.

If you want to "fix" the drive then more details are needed and often I have to run GPARTED (it's a boot item and on the web so I don't write at length on it) or DBAN to wipe the drive to start over. If the drive seems broekn, then it's replaced.