How to repair bad sectors on HDD in Windows 10, 11 and safely recover data

This time, we will explain how to repair bad sectors on an HDD (hard disk) in Windows 10 or Windows 11.

If folders are not displayed, an error message appears when reading or writing data, or strange noises are coming from the hard disk, there may be a bad sector occurring for some reason.

If you notice a problem, the sooner you deal with it, the more data you can save, so please use this as a reference.

What are bad sectors on HDD (hard disk) in Windows 10 and 11?

Bad sectors on the HDD in Windows 10 and Windows 11 occur due to physical wear and tear within the hard disk.

In this article, we will explain the following about bad sectors.

• What exactly is a sector?
• What happens when bad sectors occur?

What exactly is a sector?

A sector is a recording unit in disk-shaped storage devices such as HDDs.

On HDDs, the disc is divided into areas, and recording is performed in each area.

First, a unit called a track is a disc divided into circular areas (like the rings of a tree). Sectors are then divided radially from the center of the disk at equal intervals.

What happens when bad sectors occur?

If a sector becomes a bad sector due to wear, etc., the sector becomes unusable.

However, just because a bad sector occurs does not mean that a problem will occur immediately.

Even if a bad sector occurs within the allowed capacity, the HDD will operate normally by using spare sectors or skipping the bad sector.

However, if the condition worsens, such as when the number of bad sectors increases, the HDD may become inaccessible.

Therefore, if a problem occurs with your HDD and it turns out that it is caused by bad sectors, it is better to deal with it as soon as possible.

Is there a way to repair bad sectors on an HDD (hard disk) in Windows 10 and 11?

Is there a way to repair bad sectors on the HDD in Windows 10 and Windows 11?

To conclude first, it is impossible to repair bad sectors caused by physical corruption on 100%.

However, in some cases, it may be possible to temporarily repair data on a hard disk that is experiencing problems due to bad sectors and retrieve some or all of the data.

For this purpose, it is better to use Windows tools and software.

Repair bad sectors with free software

There are several ways to repair bad sectors on Windows 10 and Windows 11 using free software as follows.

To be precise, it is not possible to repair the bad sector itself, so you need to rescue and restore as much data as possible.

• Repair data using ddrescue
• Repair bad sectors with HDD Regenerator

Repair data using ddrescue

ddrescue is a program that copies data.

ddrescue skips bad sectors and copies data from sectors with no problems first.

Therefore, ddrescue can be said to be a program that can rescue a relatively large amount of data even from problematic disks.

Basically, a bad sector will never turn back into a normal sector.

Therefore, it is effective to migrate the data to a normal disk, minimize the damage, and then recover that disk.

[How to copy data using ddrescue]

1. Index of /gnu/ddrescueget more ddrescue
2. Connect hard disk to SATA
3. start ddrescue
4. Enter "ddrescue -f copy source copy destination"
   (Use option "-r" to reread bad sectors)
5. Run with "Enter" key

Abort the copy operation by pressing "Ctrl" + "C" keys.
Pay attention to the order in which the copy source and copy destination are listed.

Repair bad sectors with HDD Regenerator

HDD Regenerator is a software that may be able to repair bad sectors.
This software is paid, but there is also a free version.
The free version can only repair one bad sector per boot.

The paid version is currently priced at $99.99.
In some cases, it may be better to replace the hard disk with a new one.

HDD Regenerator generally cannot repair physical bad sectors, but it may be able to recover magnetic bad sector errors. However, it doesn't seem to be able to address other issues.

Please note that it is not always possible to repair the problem.

Please note that this is only a solution for minor logical failures, and the stress of running this method may also result in bad sectors.

[How to deal with bad sectors with HDD Regenerator]

1. Dmitriy Primochenko OnlineGet HDD Regenerator from
2. Purchase a license
   (Free version is also available. Only one bad sector can be repaired per boot)
3. Write programs to USB, DVD, CD, etc.
4. If HDD I/F is SATA & AHCI mode, change SATA mode to IDE in BIOS
5. Start HDD Regenerator from the media where the program was written
6. Select Normal mode or PreScan mode
   (PreScan to detect Delayed Sector)

Causes of bad sectors on HDD (hard disk) in Windows 10 and 11

The causes of bad sectors on HDD in Windows 10 and Windows 11 include the following:

• Initial failure of HDD
• HDD head damage
• Deterioration and lifespan of HDD magnetic material

Initial failure of HDD

Bad sectors exist from the time the HDD is shipped.

However, the bad sector will be replaced with a normal sector and skipped, so it will not become a problem right away.

HDD head damage

A damaged HDD head can also cause bad sectors.

The HDD head is the part used to read and write data.

If this head is damaged, it will damage the recording surface of the disc when reading or writing.

The damaged area becomes a bad sector and becomes unreadable.

Deterioration and lifespan of HDD magnetic material

Deterioration of the HDD's magnetic material can also cause bad sectors.

The magnetic material is on the surface of the disk and allows data to be read and written.

However, if this magnetic material deteriorates, it becomes impossible to read or write in that area.

What are the troubles caused by bad sectors on the HDD (hard disk) in Windows 10 and 11?

Troubles caused by bad sectors on the HDD in Windows 10 and Windows 11 include the following:

• Frequent blue screen
• There is a strange noise coming from the HDD.
• A problem occurs while starting Windows
• Error message is displayed

Frequent blue screen

One of the problems caused by bad sectors is frequent blue screens.

When a blue screen appears, an error code, etc. may also be displayed at the same time.
The error code "0xc000009c" seems to indicate that there is a defective sector on the HDD.

It is also possible that the number of bad sectors has increased so much that there are no spare sectors available to replace them.

In this case, it may be better to back up your HDD as soon as possible and replace it with a new one before it becomes damaged.

Abnormal noise from HDD

If your HDD is making unusual noises, it may also be a problem caused by the occurrence of bad sectors.

When the head is in contact with the disk, there may be a scratching sound such as a "shooing" sound.

There are also cases where sounds such as ``rattling'' or ``sizzling'' are heard.

Especially if the head is in contact with the disk, there is a possibility that it will scratch and cause many scratches.

If you hear such abnormal noises, please turn off the power as soon as possible to prevent further trouble.

A problem occurs while starting Windows

In some cases, bad sectors may cause Windows to fail to start or to take an abnormally long time to start.

If bad sectors occur in areas related to the OS, the data necessary for booting may become unreadable.

Also, if your computer takes a long time to boot, it may be because your HDD is trying to read bad sectors over and over again.

Error message is displayed

The error message may also appear due to bad sectors.

For example, messages such as "Cyclic Redundancy Check Error", "Delayed Write Error", and "Sector Not Found".

These occur when reading and writing data.

How to prevent bad sectors on the HDD (hard disk) from being used in Windows 10 and 11

If bad sectors occur on your HDD in Windows 10 or Windows 11, there are ways to prevent them from being used.

• mark bad sectors

However, if you feel that problems are starting to occur due to bad sectors, we recommend that you take measures such as replacing them immediately.

This is because if you are having problems such as not being able to read files or getting error messages, it is because the bad sectors are not being replaced.

There is a limit to the replacement processing of bad sectors, and the number of bad sectors increases until that limit is reached.

In this case, there is a high possibility that there is a physical cause for the increase in bad sectors. For example, head damage. And if you continue to use it without the cause, the damage will increase.

There are ways to avoid using bad sectors, but if you are experiencing problems like the ones mentioned above, take action immediately.

mark bad sectors

If you mark bad sectors using CHKDSK or SCANDISK, the marked bad sectors will no longer be used.

Please note that following these methods may result in data loss. Please make a backup just in case.

[How to mark bad sectors]

1. Type "cmd" in the Windows search box
2. Right click on “Command Prompt”
3. Select "Run as administrator"
4. Enter "chkdsk c:/f /r" in the window
5. Press "Enter" key
6. When prompted, "CHKDSK cannot run because the volume is in use by another process. Do you want to schedule a check on this volume at the next system startup?", enter "Y"
7. Once the check is complete, the bad sectors will be marked and skipped by the system.

Summary of how to repair bad sectors on HDD (hard disk) in Windows 10 and 11

This time, we explained how to repair bad sectors on HDD in Windows 10 and Windows 11.

Even if a bad sector occurs at a normal level, it is usually dealt with by replacing it with a spare sector or skipping it.

However, if the HDD has problems due to an increase in bad sectors, there is a possibility of data loss.

Depending on the solution, you may be able to save your data, but it's best to back up your data as often as possible.

If your hard disk is in very poor condition or contains important data, you may want to consider calling a professional instead of forcing yourself to deal with it.

It is also a good idea to try to reduce the causes of bad sectors as much as possible.
For example, being careful not to turn off your PC suddenly, or being careful not to drop or hit your PC.
Be sure to handle it as carefully as possible to prevent damage to not only the HDD but also the PC itself.