Data Recovery Tips: How to Avoid HDD Bad Sectors

As one of the main storage mediums, HDD plays a significant role in a properly working computer. Due to the delicate mechanical structure of an HDD, it can be fragile and often run into all sorts of problems. Bad sector is one of the common causes of a malfunctioning HDD.

A bad sector is a cluster of storage space of the hard drive that appears to be defective and doesn't respond to read and write requests. There are two types of bad sectors: physical bad sector and logical bad sector. Physical bad sector means the cluster of storage space is physically damaged and can't be repaired. Logical bad sector is often detected because the system finds the content of the sector doesn't match the error-correcting code, which may indicate something is wrong. Logical bad sector is also called soft bad sector because it can often be repaired by using disk repairing utilities.

Signs and symptoms of bad sectors

1. You get repeated and frequent corrupted data errors. Data in bad sectors will not respond to read/write requests, causing file corruptions when operating system attempts to access them.

2. You hear frequent clicking noises from the hard drive. The clicking noise indicates that the read/write head of a hard drive is trying to access data from the bad sectors but is unable to do so.

3. Formatting process completely halts at a certain point. Bad sectors can disrupt the formatting process, causing the "Windows was unable to complete the format" error.

4. Automatic execution of Chkdsk command on start up.

5. Unable to finish partitioning process using fdisk command line.

6. Unable to boot system. You see errors like "Sector not found" or "General error in reading drive C:" when you try to start the system. This could be caused by either boot sector virus infection or bad sectors.

Causes of bad sectors

1. Improper shutdown of a computer. If your computer suddenly shuts off due to a power outage or a pulled power cable, it’s possible that the hard drive may have shut off in the middle of writing to a sector. In some cases, it’s possible for sectors on the hard drive to contain data that doesn’t match their error-correction code — this would be marked as a bad sector. It may also cause the read/write head to touch the platter, resulting in damaged magnetic surface.

2. Damage to the electronic circuit. If you touch the circuit of a hard drive with your bare hand, the static electricity you carry may damage the delicate parts of the hard drive.

3. Airborne dust. While dust particle will not directly damage the coating on the platter,it may disrupt the thin layer of air flow that keeps the read/write head afloat and not crashing into the platter.

4. Other external force impacts will also lead to the head scratching or touching the platter, damaging the data layer.

Windows has a built-in Disk Check tool that can scan your hard drives for bad sectors, marking physical bad sectors so it will be skipped and repairing logical bad sectors to make them usable again.

If you suffer from severe physcal bad sector problems and wish to recover lost data, never attempt to do this on your own. You need help from professional data recovery companies with cleanrooms and all the right tools to make sure you can re