Fix Bad Sectors on a Hard Drive: Step-by-Step Guide

Bad sectors are damaged areas on a hard drive where data can no longer be read or written reliably. This guide shows you how to identify, attempt to repair, and isolate bad sectors using built-in Windows tools, helping you extend the life of your drive and recover access to your files. Before starting, back up any critical data you can still access, as the repair process can stress a failing drive.

What You’ll Need

A Windows PC (Windows 10 or 11) with the affected hard drive connected
Administrator account access
An external storage device for backing up important files (recommended)
Patience – the process can take hours depending on drive size

Step-by-Step

Back up your data first. Copy any important files to an external drive or cloud storage. If the drive has many bad sectors, copy files individually rather than doing a full image backup, which may fail.
Run a basic error check. Open File Explorer, right-click the drive, select Properties, go to the Tools tab, and click Check under Error Checking. If Windows asks to scan, let it run. This fixes some logical errors and marks bad sectors.
Open Command Prompt as Administrator. Press Windows key, type cmd, right-click Command Prompt, and select Run as administrator.
Run CHKDSK with repair options. Type chkdsk C: /f /r /x (replace C: with your drive letter). The /f flag fixes errors, /r locates bad sectors and recovers readable data, and /x forces the volume to dismount first. Press Enter.
Schedule the scan if needed. If the drive is in use (e.g., your system drive), CHKDSK will ask if you want to schedule it for the next restart. Type Y and press Enter, then restart your computer.
Wait for the scan to complete. CHKDSK runs in multiple stages. It may take several hours on large drives. Do not interrupt it – let it finish. You’ll see a summary of how many bad sectors were found and repaired.
Check the results. After CHKDSK finishes, open Event Viewer (type eventvwr in the Start menu), go to Windows Logs > Application, and look for the most recent Wininit event with source Chkdsk. It lists detailed results.
Re-run a quick check. After the repair, run chkdsk C: (without flags) to see if the drive still reports bad sectors. If it shows 0 KB in bad sectors, the repair worked.
If bad sectors persist, isolate them. Download a free utility like CrystalDiskInfo to check the drive’s SMART health. If the drive is failing, copy off all data and replace it. If it’s a secondary drive with a small bad region, you can create a partition that avoids that area using Disk Management (right-click Start > Disk Management).
Consider a full format. If CHKDSK can’t fix everything, a full format (not quick format) rewrites every sector, which can sometimes remap bad sectors. Right-click the drive in File Explorer, select Format, uncheck Quick Format, and run it. This erases all data.

Common Mistakes

Interrupting CHKDSK – stopping the scan mid-way can leave the filesystem in an inconsistent state.
Skipping the backup – if the drive fails during repair, you lose everything.
Using the wrong drive letter – double-check you’re scanning the correct drive to avoid wasting hours.
Ignoring SMART warnings – if the drive is mechanically failing, no software fix will save it long-term.
Running CHKDSK on an SSD – bad sectors on SSDs are handled differently; CHKDSK can cause unnecessary wear. For SSDs, run the manufacturer’s diagnostic tool instead.

Tips

Run CHKDSK regularly (monthly) on drives you rely on, especially if you notice slowdowns or file corruption.
Keep your drive cool and avoid physical shocks – both contribute to bad sector formation.
Use chkdsk /scan first (Windows 10/11) for a quick online scan without repair, to gauge the severity.
For external drives, connect via USB 3.0 or SATA directly – flaky connections can cause false bad sector reports.
After a successful repair, monitor the drive’s SMART attributes (Reallocated Sectors Count) using a tool like CrystalDiskInfo. If the count keeps rising, replace the drive.

Troubleshooting

CHKDSK says “The volume is in use by another process” – close all programs that might be using the drive (antivirus, indexing, etc.), or schedule the scan for restart as prompted.
CHKDSK freezes or stalls – this is normal on drives with many bad sectors. Wait at least 30 minutes before assuming it’s stuck. If it’s been hours with no progress, the drive may be failing; force-quit and back up what you can.
Windows can’t access the drive at all – try connecting it to a different port or computer. If it still won’t mount, use a Linux live USB to attempt data recovery, or consult a professional data recovery service.
CHKDSK finds bad sectors but can’t repair them – this means the sectors are physically damaged. The drive is likely dying. Copy off all data immediately and replace the drive.
Error 0x80070570 or similar – this indicates file corruption from bad sectors. Run sfc /scannow after CHKDSK to repair system files, and consider reinstalling affected applications.

Frequently Asked Questions

Can bad sectors be truly repaired?

Software can’t physically repair a damaged platter surface. What CHKDSK does is mark bad sectors so the drive’s firmware remaps them to spare sectors, effectively hiding them. The data in those sectors is usually unrecoverable.

How long does CHKDSK take?

It depends on drive size and health. A healthy 1TB drive with /r can take 2–4 hours. A failing drive with many bad sectors can take 8+ hours or appear to hang.

Will CHKDSK delete my files?

No, CHKDSK does not delete files. It attempts to recover data from bad sectors and repairs the filesystem structure. However, files that were stored in unreadable sectors may become corrupted or lost.

How often should I run CHKDSK?

For a healthy drive, once every few months is fine. If you notice frequent file corruption, crashes, or slow performance, run it immediately and check SMART health.

Can I use bad sector repair software instead of CHKDSK?

Yes, tools like HDD Regenerator or Victoria can sometimes recover data from bad sectors that CHKDSK skips. However, they’re not free and don’t guarantee success. CHKDSK is the safest first step.

When should I just replace the drive?

If SMART reports a high or rapidly increasing Reallocated Sectors Count, if you hear clicking or grinding noises, or if CHKDSK can’t repair the bad sectors, replace the drive immediately. Continuing to use it risks total data loss.

General steps for current mainstream versions; menus can differ by device and version. See the disclaimer or report an error.

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