How to Fix Bad Sectors on a Hard Disk in windows? (by 4 users)

Hello herself,

A hardisk contains a special chip on it's board that contains information about it's operationg parameters and so on. Also there is a part at the begining of each cylinder that also contains a record of every sector. A phisical bad sector will be recorded there first, and the hard-disk will ignore it. This isn't something that you see in software utilities, it is being done by the hard-disk's firmware and microcontrollers. However when the space allocated for bad sectors recordings gets full, the visible problems get to appear. Only then you find out about bad sectors and only the bad's that appear after. What you see is something like the top of the iceberg. A back-up should be made, as it is going to get worse, fast.
There are 2 types of bad sectors.

1 Logical bad sectors. This occurs if a cylinder ( one of the disks inside of a hard-disk) is magnetised improperly due to errors. The hard disk works in the same way as od tape recorders. It magnetises at diferent potentials some portion of a disk to store information. If it does that rong due to some software errors or improper shutdowns it woun't be able to read the improper magnetised zones next time. The software (windows) will call this "bad sectors" and will mark them, never to be used. The software doesn't make the difference between logical bads and phisical ones, it just knows it can't read data from there. Logical bad's CAN be fixed, because they're just improper magnetised areas of the hard-disk. Utilities like hard-disk regenerator will help you with that by remagnetising those areas. Note that windows doesn't know how to get rid of these, it only marks them or attemt to read from it again, but doesn't actually do something to recover them.

2 Phisical bad sectors. They occur when the hard-disk heads touch the disks and scrach them. This is the more often case. Take note that hard-disk's aren't vacuumed and inside them there isn't ..void. They are presurised but they actually "breath" from the surrounding space. You may find on some hardisks some small holes with a sticker near them saying not to cover them.
When a hard-disk is powered on it creates some strong air currents inside it. The reading/writing heads will actually hover over the disk surface not touching them. When,however, due to changes in the rotating spead of the hard-disks this air curents are decrasing in intensity, the reading/writing heads woun't be able to "hover" and could come down closer to the disks and actually scrach them. This produces circular scratches over a disk, and those can't be recovered. Dust inside a hard-disk is just as leethal, as it will scratch the disks surface.

I hope you know have an ideea about bad sectors. If you need more assistance in bad sectors you may post back.
Also sorry for my bad english as I am from a non-english speacking country.