chkdsk Command with Examples

Introduction

The chkdsk command (short for Check Disk) is a Windows utility that scans disks and reports on the state of the partitions and the stored data. Use chkdsk to repair drives and recover data from the damaged drive sectors.

This tutorial will show you how to use chkdsk to detect errors and repair your Windows drives.

Prerequisites

• Windows machine.
• User account with admin privileges.
• Access to Command Prompt or PowerShell.

chkdsk Syntax

The chkdsk command takes one or more arguments. The basic chkdsk command syntax is:

chkdsk [volume] [switches]

Volumes and switches are optional. Enter the base command to start the scan:

chkdsk

When you run chkdsk on its own, it scans the drives in read-only mode.

However, running chkdsk without the /F parameter on an active partition sometimes produces false positives, so this method of partition scanning is not recommended.

chkdsk Options

Expand and customize the chkdsk functionality by providing additional command-line arguments. The table below contains the list of the available options.

Option	Description
[volume]	Specifies a volume for chkdsk to scan. Follow the volume letter with the : symbol (e.g., C:).
/B	Clears the list of bad clusters, rescans the drive for errors, and recovers readable information. Use this switch only with NTFS partitions.
/C	Speeds up the scanning process by skipping over folder structure cycles. Use the switch with NTFS partitions only.
/F	Fixes errors on the disk.
/forceofflinefix	Skips routine indexing checks and performs a fast drive scan. Use this switch with NTFS partitions only.
/I	Skips routine indexing checks and perform a fast drive scan. Use the switch with NTFS partitions only.
/L:[size]	Changes the log file size. If you do not state the size, /L prints the current file size. Use the switch with NTFS partitions only.
/offlinescanandfix	Scans and fixes the volume offline.
/perf	Speeds up the scan by using more system resources. Use the switch only with NTFS partitions alongside the /scan option.
/R	Scans for bad sectors and recovers non-corrupted information. If the /scan option is not included, chkdsk also attempts to fix the disk errors.
/scan	Runs an online scan. Use this switch with NTFS partitions only.
/spotfix	Shows the paths of all the files on the disk on FAT and FAT32 partitions. It also shows cleanup messages on NTFS partitions.
/V	Shows the paths of all the files on the disk on FAT and FAT32 partitions. It also shows cleanup messages on NTFS partitions.
/X	Force-dismounts the drive and fixes any errors on the disk.
/?	Shows chkdsk help.

How to Run chkdsk

chkdsk is a command-line interface (CLI) tool available in Windows Command Prompt and Windows PowerShell. The following steps show how to access PowerShell with the administrative privileges to run the command:

1. Type PowerShell in the bottom search bar. The Windows PowerShell item appears in the list of programs.

2. Select Run as Administrator in the pane on the right side.

The PowerShell window opens.

chkdsk Examples

Combining the available switches with the chkdsk command helps narrow the scan target and perform custom scans. The following are examples of using the chkdsk command.

Check Disk without Fixing Errors

If you want to scan the drive without making any fixes, use:

chkdsk C: /scan

This command scans for errors but does not attempt to fix them. It's useful for diagnostics without making changes.

Scan for Bad Sectors

Scan the C: drive for bad sectors and recover the readable information. Run the following:

chkdsk C: /R

If chkdsk cannot lock the drive, it displays the following message.

Type Y and press Enter. Then, restart the computer to complete the scan.

Check Disk and Fix Errors

Check and fix file system errors on the C: drive with:

chkdsk C: /F

The command checks the file system for errors, such as issues with file or directory entries. If it finds any file system errors, it automatically fixes them.

The command cannot run on the C: drive while Windows is actively using it because the C: drive is the system drive used by the operating system.

Windows asks if you want to schedule the check to run during the next restart. Type Y and press Enter to schedule the check for the next reboot.

Force Offline Fixes for NTFS C Partition

Run an online scan of the NTFS-formatted C: partition but force chkdsk to perform all the fixes offline:

chkdsk C: /scan /forceofflinefix

The output shows the scan stages.

If the scan finds any errors, they are repaired after the drive is dismounted. If there are no errors, chkdsk displays a report:

Scan and Fix Drive Using Maximum Resources

Scan and fix drive D: bad sectors online, using the maximum allowed amount of system resources. Run the following:

chkdsk D: /R /scan /perf

Scan Drive for Errors with Forced Dismount

Scan for disk errors on the drive D: and force the drive to dismount if necessary. Run the following:

chkdsk D: /X 

Scan Drive and Ignore Bad Sector Records

Perform an online scan of the C: drive to reevaluate previously marked bad clusters and update the error records without requiring a reboot:

chkdsk C: /B /scan

The command issues an error because the C: drive is the system drive, and it's currently used by the operating system and running processes. chkdsk cannot obtain exclusive access, so it needs to scan and update certain parts of the file system.

The command can run during the next system restart when the operating system isn't loaded.

Conclusion

This tutorial presented the chkdsk command, a Windows CLI utility for scanning and repairing disks. It explained how to scan and recover bad sectors and fix disk errors on your Windows system.

Next, learn more about data corruption and how to prevent it.