Disk bad sector is the most common issue of hard disks. This article introduces how to check the bad sectors and the situations you may encounter when bad sectors issue happens to your hard disk.

After using the hard disk for a long time, users may find there are different kinds of hard disk problems. And the disk bad sector is the most common issue. There are various problems that can cause hard disk bad sectors: poor quality or aging, physical damage or shock, excessive heat, etc. 

Hard Disk Bad Sectors 1

Hard disk is widely used to store massive data. The data may be lost if there are some bad sectors on the hard disk. To avoid some losses brought by data loss, users need to timely back up some important data.

Tip: When it comes to backup data, you can try using MiniTool ShadowMaker Free. It is an all-in-one system backup and data protection solution.

New Hard Disk

Each new hard disk more or less has bad sectors. But these bad sectors are hidden in the P or G table by manufactures, thus users are unable to access them via general software. G table, user-level list, can store several hundred to about a thousand bad sectors. P table, plant-level list, can store 4000 bad sectors. 

Check Hard Disk for Bad Sectors

The hard disk will be abnormal if it has some bad sectors. For example, some sorts of strange voice suddenly appear, or users cannot partition or format this hard disk. Do you know how to check hard disk for bad sector? In this post, we recommend you to use MiniTool Partition Wizard and its “Surface Test” function.

At the same time, we will show you the situations you may encounter when bad sector issue happens to your hard disk. Please see the following introduction:

  • When users open and run the file, they may find the speed is very slow, or they can obviously hear strange noise, or sometimes they receive a prompt they cannot read and write file.
  • If the hard disk automatically scans itself when running the computer, there are some errors on the hard disk. If disk scan cannot be completed, the hard disk has bad sectors. In other situations, scan hard disk is performable, but some locations are marked in red “B“.
  • The hard disk cannot boot. Although users can see the drive letter after booting from the floppy disk or CD-ROM instead of the hard disk, they are unable to manipulate the hard disk. More than that, even if users boot from floppy disk, they can’t see the drive letter.
  • When reading a file or running a program, the hard disk will repeatedly read the data, or it will take quite a long time to complete this task. At sometimes, users just see a blue screen.
  • Some sorts of strange voice suddenly appear and then replace the normal friction voice.
  • The system cannot boot normally, and “Sector not found“, “General error in reading drive C” or other tips in the condition of excluding virus infection appear.
  • Users failed to format the hard disk.
  • As long as we are running the computer, the system will automatically run Scandisk to scan the disk to check some errors.
  • Users failed to turn to FDISK to partition the hard disk.
  • Users are unable to boot the system via hard disk.

It is possible to shield these bad sectors if you want to. Here, you can read this post to search one solution: If a Disk Read Error Occurred in Windows 10/7/8, Try These Solutions

To Repair Bad Sectors

Please select the drive letter in Windows Explorer, choose “Properties” from the right-click menu, and then make a full scan of the hard disk in the “Tools” option.

If failed, users can try booting the computer via Windows 98 startup disk, and then run the DOS version of “Scandisk“.

Sometimes, users can reformat the hard disk to repair some bad sectors. But, this method is not very effective.

If users cannot repair bad sectors, they can hide them. First, users should find out the general bad sectors range. Next, format it and record the percentage when bad sectors appear, and then calculate the approximate location of bad sectors according to the partition capacity. Or, users can resort to the “Scan Disk” to full scan the disk to determine the location of bad sectors. After that, users should divide the space as a separate partition. Finally, hide it.

Note: Users should carefully determine the range of the bad sectors. Otherwise, bad sectors will be used again or some hard disk space will be wasted. And, it’s recommended to backup some important data before hiding the bad sectors. 

Repartition Bad Disk

In fact, users can turn to Fbdisk to hide bad sectors. Fbdisk can repartition the hard disk which contains bad sectors, and set the space which contains bad sectors as hidden partition, and set other space as available partitions. If sector 0 of the hard disk is bad, the entire disk cannot be used. Aiming at this situation, users can turn to the PCTOOLS9.0 DiskEdit to hid the useless 0 sector, and then replace it with the 1 sector.

  1. After booting the computer with Windows 98 startup disk, users can run the DE.EXE. Next, they can choose “Configuration” from the “Option” menu, and then press the spacebar to remove the trick. After that, select the drive, choose “Physical“, press the spacebar, and press the Tab key to switch to the “Drive” items. Finally, select the hard disk, and then click “OK” button.
  2. Open the “Select” menu, and choose “Partition Table“. Partition 1 is C drive which starts from the 0 cylinder. At this time, users just need to change the beginning cylinder from 0 to 1. And save it.
  3. Turn to the CMOS to detect the hard disk, and then format it. After formatting, users can write the partition information from 1 sector.


Reasons for Bad Sectors:

There are many reasons contributing to hard disk bad sectors: improper shutdown of Windows, defects of the hard disk (including general surface wear, pollution of the air inside the unit, or the head touching the surface of the disk), poor quality or the aging of hardware (such as a bad processor fan, dodgy data cables and overheated hard drive), and malware.


There are two types of bad sectors – hard and soft. Hard bad sectors are the ones that are physically damaged, and it cannot be repaired.

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