How to run chkdsk in Windows

What is chkdsk

The name of the chkdsk command comes from check disk. You can use this Microsoft® Windows® utility
to analyze the integrity and reliability of systems storage devices. Originally intended for hard drives,
you can use the command on any storage device that uses a filesystem and formatting.

chkdsk performs the following activities:

  • Checks the hard drive for potential failure due to read or write errors.
  • Repairs errors found by moving stored data to other areas of a drive, which are physical locations
    called sectors.
  • Attempts to salvage any bad or unreliable data stored in the sector and move it to another sector. The
    operation then marks the original sector as unusable and unavailable for the operating system.
  • Scans the filesystem and analyzes the integrity of the files, the filesystem, and the file metadata on the drive.
  • Fixes misaligned time stamps, file size data, and security flags on files on the drive.
  • Conducts a complete scan of the drive, accessing and testing every sector of the hardware. Because this method
    is a more thorough check, you should perform it in a maintenance window. The operation divides a hard drive
    into logical sectors, which are defined areas of the drive where a certain defined quantity of data is stored.
    If sectors develop soft errors, the operation rewrites the data.


You must have an administrator account to use chkdsk.

Invoke PowerShell or the command prompt

To launch Windows PowerShell®, use the following instructions:

  1. Press the Windows Key + X to bring up the power users menu in the Start menu.
  2. Select PowerShell from there or type powershell at the Start menu.
  3. Right-click the PowerShell icon and launch it as administrator.

To use the command prompt, perform the following steps:

  1. Click the Windows key and type cmd.
  2. Right-click the command prompt application and launch as administrator.

Invoke chkdsk

To invoke the utility in read-only mode, enter chkdsk followed by a space, and then the letter of the
drive you wish to examine. In this mode, you can use the utility safely on an active system because no
changes or repairs occur. chkdsk simply runs in diagnosic mode and displays the results when completed.
Because the utility makes no changes, you don't need administrator privileges. As a best practice, you
should run chkdsk in this mode before you add arguments to repair. To run chkdsk on system drive C:,
use chkdsk c:.

Commonly used parameters

The following chkdsk parameters are most commonly used:

  • chkdsk C:: Performs a read-only check, displays errors found, with no administrator privileges needed.
  • chkdsk /f /v: Runs after a reboot, and checks and fixes errors, in verbose mode.
  • chkdsk /r: Runs after reboot and assumes the functions of /f, relocates bad sectors.

chkdsk operation and parameters

The following description of the operations and parameters might help you with your use of chkdsk:

Syntax: chkdsk [drive:] [parameters]

Checks a disk and displays a status report.

chkdsk [volume[[path]filename]]] [/F] [/V] [/R] [/X] [/I] [/C] [/L[:size]] [/B] [/scan] [/spotfix]

chkdsk has the following parameters:

  • volume: Specifies the drive letter (followed by a colon), mount point, or volume name.

  • filename: FAT/FAT32 only: Specifies the files to check for fragmentation.

  • /F: Fixes errors on the disk.

  • /V: On FAT/FAT32: Displays the full path and name of every file on the disk.
    On NTFS: Displays cleanup messages, if any.

  • /R: Locates bad sectors and recovers readable information (implies /F, when /scan not specified).

  • /L:size: NTFS only: Changes the log file size to the specified number of kilobytes. If size is not
    specified, displays the current size.

  • /X: Forces the volume to dismount first, if necessary. All opened handles to the volume are invalid (implies /F).

  • /I: NTFS only: Performs a less vigorous check of index entries.

  • /C: NTFS only: Skips checking of cycles within the folder structure.

  • /B: NTFS only: Re-evaluates bad clusters on the volume (implies /R).

  • /scan: NTFS only: Runs an online scan on the volume.

  • /forceofflinefix: NTFS only: Must be used with /scan. Bypass all online repair. Queues all defects
    for offline repair, which you run with chkdsk /spotfix.

  • /perf: NTFS only: Must be used with /scan. Uses more system resources to complete a scan as
    fast as possible. This might have a negative performance impact on other tasks running on the system.

  • /spotfix: NTFS only: Runs spot fixing on the volume.

  • /sdcleanup: NTFS only: Garbage collect unneeded security descriptor data (implies /F).

  • /offlinescanandfix: Runs an offline scan and fix on the volume.

  • /freeorphanedchains: FAT/FAT32/exFAT only: Frees any orphaned cluster chains instead of recovering their contents.

  • /markclean: FAT/FAT32/exFAT only: Marks the volume clean if no corruption was detected, even if /F not specified.
    The /I or /C switch reduces the amount of time required to run chkdsk by skipping certain checks
    of the volume.