In my segate 80GB HDD there was 4bad sector. They were making so much problems, even was corrupting OS without any notice. Now i did a FULL ERASE by using seatools of segate. After that CHKDSK also not finding any badsector. And the LONG TEST of seatools also not finding any bad sector. Actually i was wondering to know how a physical problem of HDD is repaired by FULL ERASE. Anyone have any info regarding this please share with me.
Its magnetic media, not necessarily a physical defect. Maybe some reinitialization since its able to set everything to zero it could use a stronger field without worrying about damaging adjacent data. I would still replace it. once a drive stats going it tends to die.
If the bad sector is not fixed by seatools' 'full erase' then the firmware inside the drive will record its location and remove it from the table of available storage sectors. The bad sector will become effectively invisible to the operating system and never used.
However, unksol has it right. Once a drive starts to go bad it is on the way out - replace at your earliest opportunity.
Historically, hard drives were very expensive and they had to have methods to keep them going. Now they are cheap-as-chips so first signs of badness = replace.