Solve Hard Disk Bad Sectors step by step

Source: Internet
Author: User
First, we need to understand the structure and working principle of the hard disk. In general, a hard disk can be regarded as a closed optical drive. The difference is that it has multiple disks and uses a head instead of a laser head to read and write data. We generally divide disks into channels and sectors for management. In the file area, several consecutive slices of a track are merged into a cluster, and the file occupies disk space in the unit of cluster. As long as one cluster breaks down, the entire track is marked as "bad track" (marked as "B") strictly speaking. Hard Disk Bad Track has two meanings: logical and physical bad paths, the former is called a soft bad track, while the latter is a real physical bad track. It indicates that physical damage has occurred to the hard disk track. It can only be solved by changing the use of hard disk partitions or sectors. The symptoms of bad sectors are as follows:

1. at the beginning, when you open, run, or copy a file, the operation on the hard disk slows down, and the operation may fail for a long time. This is not necessarily a bad track, however, you must be vigilant. If you use a variety of detection tools to find a bad track, you can minimize it.

2. gradually, the Windows system prompts "unable to read or write this file". Inexplicably, the system often crashes when the hard drive lights flash, uses anti-virus software to check for no viruses, and even crashes during scanning, if you are more careful, you can also find that the hard disk head is located in a certain area for a long time or the disk reading is abnormal at the same time. If this happens, you can almost determine that the hard disk has a bad track.

3. if you have not noticed the above situation, but the Scandisk disk program starts to run automatically when you start the system, it prompts you that an important error needs to be fixed on your hard disk. In this case, if the soft bad track occurs, generally, Windows scans and fixes the problem. However, if it is a physical bad track, it is very slow. Although the scan can pass, the "B" mark (meaning bad) appears ), it indicates that it has a bad track, and the scan cannot be completed even if it is serious.

4. the most serious problem is that the hard disk cannot be booted when the computer starts. After the disk is started with a floppy disk or a CD, you can see the hard disk drive letter, but you cannot perform operations on the disk or the operation is incorrect or you simply cannot see the drive letter, indicates that the hard disk may have a bad track, and the screen prompts "harddiskdrive failure" "Hard drivecontrollerfailure" or similar information, it can be determined that the hardware of the hard disk drive or hard disk controller is faulty; when reading or writing a hard disk, the system prompts "sectornotfound" or "general error in readingdrive C" and other similar error messages.

2. Repair bad sectors:

For logical bad channels, we can fix them. For physical bad channels, we should adopt an isolated approach to minimize losses and prevent further spread of bad channels.
We can use the tools provided by the operating system and some dedicated hard disk checking tools to find and fix the logical Bad Sectors of the hard disk. For example, the Scandisk disk scanning program provided by Windows finds the most commonly used tool for the logical Bad Sectors of the hard disk, however, our common format commands cannot fix any bad sectors on the hard disk. if the system does not scan the disk at startup or cannot enter the Windows system, use the corresponding drive letter, such as ": "Run Scandisk *: (* indicates the drive letter to be scanned ). Other such as the NDD "disk doctor" in the Norton toolbox, but these are only for logical bad channels. Do not try this method to fix Physical Bad channels. If you use the above method, it will increase the number of bad channels, the correct method is to use the following method:

Method 1: Use partitionmagic, diskmanager, and other software.

For example, partitionmagic partition software, first scan the disk with the "check" command in partitionmagic4 or the disk scanning program in Windows to determine the location of the bad cluster on the hard disk, select "Advanced/badsectorretest" under the operations menu to hide the partition where the bad cluster is located to avoid misoperation in windows. This function is implemented through the hidepartition menu item. This can also ensure the normal use of disks with severe bad sectors.

Method 2: Use the DOS partition command fdisk and format.

The specific method is to first find out the disk capacity. For a faulty disk, use fdisk to split it into a C disk and format it with format. When the disk fails to be repaired, the format is always fixed, in this case, record the percentage, use 'ctrl + break' to forcibly terminate the task, use the total disk capacity × percentage to obtain the normal disk capacity, and use fdisk to draw a logical disk, estimate the approximate size of the following disk to the bad track, which is about 10%, and then divide a logical disk. This small disk does not need to be formatted and deleted after work is completed, in this way, the bad track will jump over.
Example: A 10 Gb hard disk is blocked when it is formatted to 10%. Press 'ctrl + break' to forcibly terminate the disk, run fdisk to create a 990m DOS partition as a drive C (this is to leave some space for the bad track), and then create a m logical drive D, create a Logical Disk e for the remaining 10% m and exit fdisk to run format E: if the format reaches, then use fdisk to create a 88m edisk, 10 mb f disk, the remaining 7900m as G disk. Repeat the above operation until the operation is completed. Then run fdisk to delete the 10 m D and F disks. Then, the rest is the good disks with no bad channels.

Method 3: Use some specialized bad disk partitioning tools, such as fbdisk.

Fbdisk is a software dedicated to discovering and isolating bad channels under DOS and then re-partitioning. First, create a floppy disk that can be started to DOS, place fbdisk on the floppy disk, and use it to guide the system, note that the system can only mount one hard disk to be repaired and connect it to the primary hard disk. After Entering dos, as long as the hard disk can be found, fbdisk will be run and the program will automatically find the bad path, and partition, if you accept it, press y, and the software will automatically process the hard disk.
There is also a special bad track, such as the system display "track 0 bad, diskunusable" means zero track damage, we all know that 0 sector is the most important place, after the damage, it cannot be used at all. In fact, you can block the 0 sector and replace it with the 1 sector. Such software is pctool9.0 and nu8, and pctool9.0 is used as an example:
A 40 Gb hard disk causes the above problem. after starting the computer with the disk, run the de.exe file under the pctool9.0 directory, select the driver from the main menu select, select physical from the drivetype item, and select by space, press the tab key to switch to the driver item, select harddisk, press OK and return to the main menu. Open the Select menu. partitiontable is displayed. After you select the table, information about the hard disk partition table is displayed. The hard disk has two partitions. Locate the partition C, which starts from the hard disk's 0 cylinder. Then, you can change the value 0 of the beginingcylinder in partition 1 to 1 and save and exit, after restarting the computer, press del to enter coms settings and run "ideautodetect". You can see that cyls is changed from 782 to 781. Save and exit, and then re-partition the hard disk format.

Hard Disk Bad Track repair method

Bad hard drive channels seem to be a tough word, because they often mean the dual loss of hard drive decommission and data loss. As the disk density and speed increase, the hard disk seems to become more delicate. Bad Sectors are common and troublesome hard drive faults. When a bad track occurs on the hard disk, does it mean this hard disk is irretrievable? This is not the case.

I. Hard Disk Bad Track Detection

If some sectors on the hard disk cannot be read, written, or accessed normally, it is generally called a bad sector, which is often referred to as a "bad track ". The appearance of bad sectors on the hard disk is complicated. Some are logical errors caused by abnormal verification codes, sector identifiers, and address information recorded in the slice. For example, some viruses forcibly place bad blocks on some hard disk sectors, so that the system cannot use these sectors. Some are physical damages caused by abnormal impact and other causes. When the hard disk has a bad sector, the hard disk may experience slow read/write speed or even errors, abnormal sound, failure to boot the system from the hard disk, failure to complete advanced formatting, and other symptoms, in severe cases, the entire hard disk of the boot system cannot be used.

When a bad track occurs on a hard disk, the simplest method is to use the system's built-in disk scan function to scan the problematic disk and try to repair the bad sector. However, it has very limited functions. Generally, it can only handle some simple logic sector errors. If it encounters a real physical bad sector, its detection speed will be very slow. In this case, you can use more powerful detection software to not scan Bad Sectors of the hard disk, such as hddtest.

Hddtest is an extremely small software version, which is only 8 kb in size. However, it can only run in a pure DOS environment. before using it, you must copy it to a floppy disk of the bootable system and start it as a floppy disk. All operations of hddtest are completed in one window without too many commands and tedious operations. Press the up/down key to select the hard disk to be detected, and then press enter to start detection. Press the "Pause/bnter" key during the check to pause. Press the "ESC" key to cancel the check. The detection progress is displayed in the middle of the window. The following shows the disk Detection Status prompts for the software running status, and the bad track information in the lower right corner. Because it only has the detection function and does not repair the hard disk, when it detects a bad track, it is quite fast for other similar software. In addition, hddtest cannot manually start detection from a certain position on the hard disk, but can only perform full scanning from start to end.
2. Combine multiple swords to repair bad hard drive Channels

Even a brand new hard disk is actually not flawless and has no bad sectors. In fact, each hard disk has a certain number of bad channels in the production process. The manufacturer uses professional equipment to detect all bad channels and records them in the p-Iist (permanent defect table, you cannot access the bad sectors recorded in P-Iist. That is to say, the hard disks purchased by the end user will carry a certain number of bad channels, but this part is blocked by the manufacturer in special ways and will not affect the normal use of the hard disk, as a result, the appearance of Bad Sectors on hard disks is not as terrible as people think. In general, if the bad track on the hard disk is not too serious, in addition to sending the manufacturer for repair, you can also try some software for repair.

First, some basic hard disk maintenance tools, such as DM software of Hard Disk manufacturers and low-level formatting tools, can be used to repair some logical Hard Disk Bad channels. DM has the zero-fill and low-level formatting functions. It can reset the hard disk data and overwrite the sector checksum and ID information to fix bad sectors caused by incorrect ID information. You can use iformat to re-format the hard disk to achieve the same effect. However, these two types of software are powerless for Physical Bad Sectors caused by disk surface medium damage. In addition, software such as fbdusk can be used to automatically hide bad channels in a centralized manner to avoid the spread of bad channels, so as to extend the automatic hiding of bad channels and avoid the spread of bad channels, to extend the service life of the hard disk. The main function of fbdusk is to automatically isolate bad channels into a hidden area, and the system will no longer access the content of this hidden area in the future.

In addition to the above commonly used software, users can also use more powerful repair software such as HDD Regenerator (hddreg), hddspeed, thdd, mhdd and try hard disk bad track detection and repair work. Hddreg uses the magnetic reversal method to repair bad channels. It is said that it can repair about 60% of damaged hard disks without affecting the original data information of the hard disk, this is not what low-pole formatting programs can do. When software such as hddspeed and thdd detect bad sectors on the hard disk, it will activate the Automatic Repair Mechanism of the hard disk and allocate a backup sector to replace the Bad Sectors, the related information is recorded in the G-List (growth defect table. Hddspeed allows you to view the p-list and G-list of the IB kunteng fireball series, while mhdd allows you to view the p-list and G-List of IBM and Fujitsu hard disks. However, the GB-list of hard disks of each brand has a certain number limit, which is about five or six hundred. If the limit is exceeded, the automatic repair mechanism will become ineffective. In this case, you need to use professional software such as pc3000 to record bad sectors in the p-list. However, these professional software is expensive and features are too complex and not suitable for common users.

Hddreg can be run directly in Windows 95/98/ME. in Windows 2000/XP, you must create a boot and Repair Disk, which cannot be called directly. Create a boot disk, use this floppy disk to boot the system, and enter the hddreg software interface in the DOS state. Select the hard disk to be detected and determine the start position of the scan. Then, you can start the hard disk detection and repair. In the detection, press Ctrl + break to stop the scan. The detected bad zone is identified by "B", and the repaired area is identified by "R. If hddreg has used hddtest to scan hard drive Bad Sectors before hddreg is performed, you can directly locate and repair the bad sectors without scanning them from the beginning. The repair result is saved in the hddreg. log file. If you are using an unregistered demo version, you can only fix the first bad slice. In addition, because hddreg does not affect the logical structure of the hard disk when Repairing Bad Sectors, even if the bad sectors have been fixed, the system will still keep the previously marked bad sectors, you must use software such as PQ partition magic to repartition the hard disk to access the repaired sectors.

Hddspeed is a hard disk speed test software. It also has the hard disk detection and repair functions and can only run in pure DOS mode. After selecting the hard disk to be detected, run the "Media verify/Repair" option under the "diagnostic" menu (shortcut: Alt + M ), in the pop-up "perform media test" window, set the detection start point, end point, and detection count. Press the "r" key, set "try to repair/relocate round defects" to available, so that hddspeed will try to fix the bad track after detecting the bad track.

The thdd and hddspeed functions are roughly the same. You also need to copy the thdd main program to a floppy disk and then boot it to the pure DOS mode for running. It is quite concise with the interface. Select "surface test" to scan the hard disk. Go back to the main menu and select View defect list to view the list of detected bad channels. Press the "r" key to start repairing bad channels. "Pesponred" indicates that the bad track has been added to the G-list, and "not respired" indicates that the G-list is full and the bad track cannot be repaired. For hard disks with few bad channels, thdd's repair effect is still wrong.

In actual use, we can find that the above software has its own characteristics and shortcomings. For example, the hddspeed detection speed is faster, but the restoration speed is faster than thdd; hddreg's repair capability is stronger, but its detection speed is slow. In addition, each software has different performance for hard disks of different models and brands. For different Hard Disk Bad Track faults, we can try a variety of software and take full advantage of their respective strengths to maximize the repair of Hard Disk Bad Track Scanning, and then use the repair software to directly repair the bad sectors in the specified area, sometimes achieving twice the result with half the effort.
Iii. Conclusion

Bad Sectors on hard disks are tricky, but they are not completely irreparable. However, no software can be a panacea. If the hard disk is physically damaged, repair software with strong functions is powerless. In addition, we need to remind you that if the above software is used incorrectly, it will not be able to repair Bad Sectors of the hard disk, but may be counterproductive and the hard drive will be damaged.

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