What are bad sectors?
Bad sectors are sections of a hard disk drive that are physically damaged or defective. They can develop due to physical damage, manufacturing defects, aging, overheating, or other issues that prevent the drive from storing and accessing data correctly in those areas. Bad sectors are classified into two types:
Physical bad sectors: These are sectors with permanent physical damage on the hard disk. The damage can be to the disk platters themselves or other mechanical components. Physical damage usually happens due to mishandling, inappropriate operating conditions like excessive heat or vibration, manufacturing defects, or normal wear and tear over time. (Source)
Logical bad sectors: These sectors cannot store data due to software or file system issues, but the physical surface of the disk is fine. Logical bad sectors can occur due to sudden power loss, improperly shutting down the drive, file system errors, viruses, etc. Unlike physical bad sectors, data in logical bad sectors may sometimes be recovered. (Source)
Signs You Have Bad Sectors
There are several signs that may indicate your hard drive has bad sectors:
Computer Freezing, Crashing, or Becoming Unresponsive: Bad sectors can cause system instability and crashes, especially during read/write operations. Your computer may freeze or crash unexpectedly or fail to boot properly.
Data Corruption: Attempting to access data on a bad sector may return corrupted files or garbled data. You may experience frequent errors when opening files or find files contain corrupted or missing data.
Slow Performance: As the drive struggles to read/write from bad areas, you may notice significantly slower load times for programs and files. Operations like copying data may take much longer than usual.
According to CPU Guru Nerds, other symptoms can include frequent system freezes, sluggish operation, and errors when saving files.
Back up your data
It is crucial to back up all your important data before attempting any bad sector repair on a hard drive. Data stored on sectors that have gone bad is at high risk of being lost forever if you try to repair the drive without backing up first.
According to experts, “Monitoring the hard drive is the best option. You can start with SMART monitoring. SMART stands for Self Monitoring and Repairing Tool.”(source). SMART monitoring can identify impending drive failure and bad sectors so you can take action before it’s too late.
Backup software like EaseUS Todo Backup provides an easy way to fully backup your hard drive before attempting bad sector repair. As EaseUS recommends, “You can back up your hard drive from bad sectors by using backup software, like EaseUS Todo Backup. Step 1. Click “Create Backup” to start backing up. Step 2.”(source).
Backing up your data removes the risk of permanent data loss when repairing bad sectors. Don’t skip this crucial first step.
One of the easiest ways to detect and repair bad sectors on a hard drive is by using the built-in CHKDSK (Check Disk) tool in Windows. CHKDSK scans the drive and looks for errors in the file system and bad sectors. It can then repair some errors and mark bad sectors as unusable so that data is not stored there anymore.
To run CHKDSK, follow these steps:
- Open the Command Prompt as Administrator.
- Type “chkdsk C: /f” (without quotes). Replace C: with the letter of your hard drive that you want to scan.
- Press Enter. CHKDSK will start scanning the drive.
The /f parameter tells CHKDSK to fix any errors found. The process may take a while depending on the size of your drive and number of errors. CHKDSK will repair any file system errors it can and mark any bad sectors it finds as unusable.
After CHKDSK finishes, you can check the report to see if any bad sectors were found. While CHKDSK can help detect and repair some bad sectors, it has limitations. If your drive has a large number of bad sectors, you may need to try other options like specialized repair software or ultimately replace the drive.
Use manufacturer tools
One of the best ways to diagnose and fix bad sectors on a hard drive is to use tools provided by the drive manufacturer. Major hard drive brands like Seagate and Western Digital offer free diagnostic and repair tools designed specifically for their drives.
For Seagate drives, use the SeaTools utility. SeaTools provides a comprehensive suite of tests to diagnose drive issues and repair bad sectors. It can fix firmware problems, recalibrate heads, and remap sectors. SeaTools works with internal and external Seagate hard drives, including SSDs.
Western Digital offers the Data LifeGuard Diagnostics tool to test WD brand hard drives. It scans for sector defects and attempts to repair them. Data LifeGuard can perform quick or extended tests. The tool also provides drive information like model, serial number, and firmware version.
Using the manufacturer’s diagnostic tool is recommended over third-party apps because they are engineered to work specifically with that brand of drive. The tools can tap into proprietary drive features and firmware commands other apps can’t access. This gives them the best chance of repairing bad sectors and drive errors.
One tool that can potentially repair bad sectors on a hard drive is Spinrite by Gibson Research Corporation. Spinrite is a utility that analyzes the magnetic surface of your hard drive to identify weak spots and areas prone to failure. It then uses advanced algorithms to attempt to recover data from damaged sectors and reinforce the magnetic strength of weak areas SpinRite Data Recovery Technology.
Spinrite runs in different “levels” from 1-6, with higher levels doing more extensive testing and repairs. Running Spinrite can potentially fix sectors marked as “reallocated” by the hard drive and make them readable again. It does this by re-reading the troubled areas repeatedly, using signal processing to detect and recover data bit-by-bit. Spinrite can spend hours or even days on a single sector to strengthen the magnetic signal Can SpinRite fix uncorrectable/unreadable sectors?.
However, Spinrite cannot repair physical damage like scratched platters. It works best on sectors with weak or unstable magnetism. While Spinrite may recover data from some bad sectors, severely damaged drives may still require professional recovery or replacement.
Replace the Drive
At some point, it becomes more cost effective to simply replace a hard drive with bad sectors rather than attempt further repairs. This is especially true once the bad sector count reaches a certain threshold.
According to Reddit users, if the bad sector count continues to grow, it’s best to replace the hard drive as soon as you can afford a new one (source). Attempting repairs on a drive with expanding bad sectors will likely prove futile. The cost of extended troubleshooting and recovery services often exceeds the cost of a new replacement drive.
However, if the bad sector count remains stable over an extended period (e.g. one month), the drive may continue functioning normally (source). In this case, replacement may not be immediately necessary. Still, make sure backups are current, as the drive could fail at any time.
Overall, weighing the replacement cost versus continued repair costs will determine the right course. But growing bad sectors indicate replacement should happen soon.
Send for Professional Recovery
If you have critical data on a hard drive with bad sectors, sending it to a professional data recovery service may be your best option for recovering the data. Professional services have specialized tools and clean room facilities to repair drives and recover data. However, professional recovery can be expensive.
The average cost of professional hard drive recovery ranges from $300 to $2,500+. The cost varies based on the extent of the drive damage and the type of recovery required. Logical recovery of deleted files is on the lower end around $300-$700. Physical recovery from mechanically failed drives with bad sectors is more intensive and averages $1,000 to $1,500+. In extreme cases, a full-scale forensic recovery can cost $2,500 or more.
The pros of professional recovery are the high chance of data recovery compared to DIY methods. The cons are the high price tag. Weigh the value of your data against the cost to determine if professional recovery is warranted. Reputable companies like [Ontrack](https://ontrack-usa.com/hard-drive-recovery/) offer free evaluations and no data/no fee guarantees.
Prevent bad sectors
You can take steps to prevent bad sectors from developing and minimize further damage:
- Handle drives gently – Reduce vibration, shocks, drops, and impacts which can damage the platters. Use padded bags when transporting drives.
- Keep drives cool – Excessive heat can warp platters and degrade components. Ensure proper airflow and cooling inside your computer case.
- Defragment regularly – This consolidates data into contiguous blocks and minimizes head movements which can wear down surfaces.
- Upgrade to newer drives – Newer models have more robust components and firmware to handle defects.
- Use S.M.A.R.T. monitoring – This warns of potential problems so you can take preventative steps.
- Avoid overfilling the drive – Maintain at least 15% free space for best performance.
Following best practices like these can extend the usable life of a hard drive and avoid catastrophic failures. But bad sectors will eventually develop through normal wear and tear. So be sure to regularly back up your data as a precaution.
Here are some common questions and answers about bad sectors on hard drives:
What are bad sectors?
Bad sectors are areas on a hard drive that are physically damaged or cannot retain data. They are usually caused by manufacturing defects or gradual wear and tear over time. According to Pits Data Recovery, bad sectors can develop due to the hard drive’s read/write heads making contact with the disk platters.
Can bad sectors cause data loss?
Yes, bad sectors can lead to data loss and corruption. When a sector goes bad, the hard drive will have trouble reading or writing data in that area. Any files stored in a bad sector may become corrupted or inaccessible.As noted on Superuser, an increasing number of bad sectors often indicates a larger problem with the hard drive.
What happens if you keep using a drive with bad sectors?
It’s generally not recommended to keep using a hard drive with a large or growing number of bad sectors. According to a Quora response, bad sectors can spread, leading to more corrupted data and eventual failure of the drive. It’s best to replace the drive or attempt data recovery.
Can bad sectors be repaired or fixed?
While bad sectors can’t be repaired, their spread can sometimes be contained using manufacturer utilities or third party software like Spinrite. But this is not guaranteed. Reformatting or repartitioning a drive does not fix bad sectors either.
When should you replace a hard drive due to bad sectors?
There is no set threshold, but if the bad sector count is rapidly increasing, or critical OS files are being affected, it’s time to replace the drive. For drives with a small, stable number of bad sectors, continuing use may be fine, but regular backups are essential.