Thursday, 13 June 2013

Causes, Fixes & Prevention of Bad Sectors in Your Hard Drive?

A sector in a hard drive platter is a small cluster or area where actual data is stored. Normal hard drive can have from 1 to 6 platters and a single platter can have over millions of sectors. Including platter, any hard drive will also have heads, spindle motor, firmware, PCB etc. responsible for its smooth functioning. However, being an electronic device, hard drive may have one or more failing mechanical equipments which gives birth to data inaccessibility, permanent hard drive failure or system startup failure etc. After which, one may not able to retrieve the stored content as well as permanently looses accessibility to their system.

Bad sectors on the hard drive platter could be developed throughout its lifespan which may make OS unable to read or write information on that particular section. Moreover, bad sector would stress the read/write head of hard drive and causes subsequent delays in accessing the memory/information. As a result, hard drive will start failing, throwing system freezes or sometime gives black or blue screen of death (BSOD).

What causes bad sectors?

Sector is usually a block of information stored on the hard disk and having standard size of 512 bytes. These sectors can easily become bad due to imperfections of this real world. Though, you can found some most common causes which contributes heavily towards building bad sectors and blocks on the hard drive platter,

  1. System infected with Virus / Trojan / Malware – Any malicious computer program can physically harm your computer and damage surfaces of the platter or inject wrong information on the sector. However, Some DOS attacks were used to misguide operating system to treat sector as bad even if they weren't.
  2. Abnormal Shutdown: Not properly shutting down the PC may results in wrong positioning of read/write head which tends to move around the platters when system is running. Sometime, sudden system shutdown due to power failure could make platters to get in contact with the read/write arm and damage that area called sectors.
  3. Power Surge: Improper power supply or not using the reliable electricity medium causes hard drive equipments to be overheated sometime and thus, damages the magnetic area around the hard drive platter.
  4. Aging Equipments: Being an electronic device, hard drive equipments may start wearing out and bad sectors were created over time. As this process seems bit natural and depends on the overall hard drive age, these cases are least considered but worth checking.
  5. Faulty Heads: Heads plays crucial role in retrieving or storing information on/from the platter. It keeps rotating over platter without making contacts to the platter but when it does, produces bad sectors. Shaking or moving hard drive while any ongoing operation could make the head to get in contact with the platter and again, produces bad sectors.
  6. Manufacturer faults: Bad supplier or low quality manufacturer could deliver hard drive with poor quality equipments which reduces overall lifespan of your hard drive. Bad sectors were developed quite frequently on hard drive with bad equipments. Most often, bad sectors were already created when the drive is first manufactured.
Once the bad sector is developed, it starts damaging nearby sectors and soon make your whole hard drive with thousands of bad sectors. You can use various hard disk checker utility like S.M.A.R.T. To check hard drive for bad sectors as well as other crucial parameters like spin rotation, heat, equipments status and many more.

Type of Bad Sectors
There are usually two types of bad sectors took place in modern as well as traditional hard drives:

Hard or Mechanical or Physical are the one caused by heads after coming in contact with platter surface of the hard drive. For ex, if the computer is bumped or dropped while reading/writing data from/to the disk would make hard drive heads to crash or damage the area. Extreme heat, faulty heads, dust or other ageing equipments could also contributes heavily towards hard bad sectors.

Once the hard bad sectors is created, it can only be prevented, neither removed or reformed. Best bet is copy/save all your important stuff into another hard drive and replace the drive as soon as possible to stay away from various catastrophic data loss situations.

Though, if your hard drive fails due to hard bad sectors and you've lost any or all your important data, using data recovery services would be the last hope. Highly cleaned room with skilled equipments where special treatments were used to carefully open hard drive equipments and recover data from the storage area.

Soft or logical bad sectors
are less drastic and delivers minimum harm to your PC or the stored data. It is created when an error correction code of a sector can't verify the content of the same sector due to virus/threats injection on the BIOS section, improper system shutdown or directory structure corruption.    

Soft bad sectors can be repaired by using low level formatting (quick format) or disk check/repair tools which fills zero's in all the soft bad sectors. Disk wiping process is pretty effective and completely removes soft bad sectors around the hard drive, however you might permanently lose the stored data and data recovery isn't possible even by using professional recovery program. 

How to repair bad sectors?
There are choices to repair bad sectors by using either inbuilt utility or software provided from third party. As there is no guarantee of repairing bad sectors, you can still try any of the options mentioned below.

Using Inbuilt Utility
Various inbuilt check disk utility is available to check hard drive health status or any running issues and repair them immediately. Microsoft provided this utility for free of cost with Windows to help troubleshoot file system errors, scan and fix bad sectors found around the hard drive.


Running check disk utility is completely safe and doesn't harm overall functioning of your PC. As check disk utility will perform scan and recovery concurrently, this process might takes time little longer than usual.

Here's how you can start check disk utility in your PC:
  1. Double click on My Computer  from the desktop or press 'window button + 'E'.
  2. Right click on the desired drive you want to check and choose properties. Note:You can't check and repair all the drive at once.
  3. From the opened properties window, select Tools tab and click on Check Now.
  4. Check disk box will open containing options like Automatically fix file system errors and Scan for and attempt recovery of bad sectors. Mark both the options or can leave the first one only if you wants to check only hard drive for bad sectors and repair it.
  5. Click on Start to initiate check disk operation.
  6. Enter administrator password if requested and click OK.
  7. Wait for sometime and then restart PC once the operation is completed successfully.
Using third party software

Spinrite is a professional hard disk check and repair utility suitable for all the latest Windows operating system and works effectively on FAT, NTFS and Linux formatted volume. The software is self explanatory and requires simple steps to boot from DOS environment and repair almost any kind of bad sectors.

             spinrite v 6

Note: Spinrite could costs your around $ 89 USD.

Preventing bad sectors in future

Below are the precautions steps you could take to avoid bad sectors from being developed around your hard drive,
  1. Use inbuilt disk defragmenter utility to stabilize operations and reduces stress from heads. Run this utility at least once or twice in a month or schedule it to run periodically. It also helps in managing disk spaces and thus, reducing overall burden from the heads.
  2. Always use, professional and recommend anti virus software to keep your system clean and malware free.
  3. Avoid bumping or throwing during ongoing operations.
  4. Use system in cooled and dust free environment.
  5. Use standard cables or connecting media for longer durability.
  6. Use proper shutdown or standard way to turn your system off. Use UPS or similar power backup devices to make sure that you always have enough time to safely shutdown your PC when the power is absent.
  7. Running OS repair utility could also shorten the occurrences of bad sectors around the hard drive.
Have you found bad sectors in your hard drive or planning to check, what utility you're using or the way you'll recommend to repair bad sectors? Don't forget sounds all this using the comment form below.