Command Reference

chkdsk /scan

Command Prompt Storage Advanced Risk: Low
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Summary

Runs an online NTFS scan to identify file-system problems without taking the volume offline.

Syntax 

chkdsk [volume:] /scan

Examples 

chkdsk C: /scan

Scans the Windows volume online for file-system errors.

Permissions

Administrator required: Yes

Run from Command Prompt opened as administrator. Use repair options only with separate approval and a verified backup.

Risk and Impact

Risk level: Low

Changes the system: No

The /scan option is diagnostic. Do not substitute /f or /r without understanding downtime, repair, and data-protection requirements.

Supported Platforms

Windows 10 Windows 11 Windows Server

Important Output Fields

Windows has scanned the file system and found no problems

No logical file-system errors were detected.

Windows found problems

The volume needs an approved repair plan and verified backup.

failed to transfer logged messages

The scan completed but could not write its report to the event log.

Common Errors

Access Denied as you do not have sufficient privileges

The terminal was not opened as administrator.

The type of the file system is not NTFS

The selected online scan option may not apply to that volume.

Related Commands

Continue troubleshooting with related diagnostic commands.

PowerShell Beginner

Get-Volume

Lists drive letters, file systems, health state, capacity, and remaining space.

Command Prompt Advanced

sfc /scannow

Scans protected Windows files and attempts to replace corrupted copies. Microsoft recommends updating and restarting Windows, then completing DISM RestoreHealth before this repair command.

Command Prompt Advanced

DISM /Online /Cleanup-Image /ScanHealth

Checks whether the running Windows image has repairable component-store corruption.

Official References

chkdsk

Microsoft Learn · Official Documentation

Open Source