Ang HDD heath na yan ay kalahatang resulta ayon sa S.M.A.R.T. (Self-Monitoring, Analysis and Reporting Technology) ng drives. Yung bad sectors (hard or soft) ay isa lang sa mga factors though kalimitan ay isang pangunahing issue. Zero % most like ly means not-useable. "HDD recovery softwares" na yung kailangan nyan though masyadong late na rin dahil 0% (extreme). You can try Spinrite, then recover data from affected HDD as external drive if there's still a chance to retrieve. Kapag ang HDD health ay bumaba ng 100%, maging alerto/mag-backup ka na at mag-umpisa kang maghanap ng kapalit - yan yung norm. (Tulad ng sinabi ng iba, kapag physical bad sector, hindi na pwedeng ayusin "kailanman" pero kung "soft" bad sector ay naaayos ng simple low level format.)