It maybe too late as the system sees an imperfect HD. I suggest you clone or make an image of the problem drive. Use "clonezilla" s/w or any imaging s/w like Norton Ghost or if you access to the HD maker's support website, they may provide similar s/w, hopefully, you can then make a back-up or save what you can. BUT!!!! as i suggested it maybe too late for user intervention, a data retrieval service maybe needed, if you can afford or deem the data super critical to be saved. Sorry, next time save or back-up data on a periodical basis.
FYI- Check the "storage forum" for s/w listed in the sticky post for possible use.