chkdsk

Article
2025-05-26
Applies to: ✅ Windows Server 2025, ✅ Windows Server 2022, ✅ Windows Server 2019, ✅ Windows Server 2016, ✅ Windows 11, ✅ Windows 10, ✅ Azure Local 2311.2 and later

Checks the file system and file system metadata of a volume for logical and physical errors. If used without parameters, chkdsk displays only the status of the volume and doesn't fix any errors. If used with the /f, /r, /x, or /b parameters, it fixes errors on the volume.

Important

Membership in the local Administrators group, or equivalent, is the minimum required to run chkdsk. To open a command prompt window as an administrator, right-click Command prompt in the Start menu, and then select Run as administrator.

Important

Interrupting chkdsk isn't recommended. However, canceling or interrupting chkdsk shouldn't leave the volume any more corrupt than it was before chkdsk was run. Running chkdsk again checks and should repair any remaining corruption on the volume.

Note

Chkdsk can be used only for local disks. The command can't be used with a local drive letter that has been redirected over the network.

Syntax

chkdsk [<volume>[[<path>]<filename>]] [/f] [/v] [/r] [/x] [/i] [/c] [/l[:<size>]] [/b] [/scan] [/forceofflinefix] [/perf] [/spotfix] [/sdcleanup] [/offlinescanandfix] [/freeorphanedchains] [/markclean] [/?]

Parameters

Parameter	Description
`<volume>`	Specifies the drive letter (followed by a colon), mount point, or volume name.
`[<path>]<filename>`	Use with file allocation table (FAT) and FAT32 only. Specifies the ___location and name of a file or set of files that you want chkdsk to check for fragmentation. You can use the wildcard characters ? and * to specify multiple files.
/f	Fixes errors on the disk. The disk must be locked. If chkdsk can't lock the drive, a message appears that asks you if you want to check the drive the next time you restart the computer.
/v	Displays the name of each file in every directory as the disk is checked.
/r	Locates bad sectors and recovers readable information. The disk must be locked. /r includes the functionality of /f, with the additional analysis of physical disk errors.
/x	Forces the volume to dismount first, if necessary. All open handles to the drive are invalidated. /x also includes the functionality of /f.
/i	Use with NTFS only. Performs a less vigorous check of index entries, which reduces the amount of time required to run chkdsk.
/c	Use with NTFS only. Doesn't check cycles within the folder structure, which reduces the amount of time required to run chkdsk.
/l[:`<size>`]	Use with NTFS only. Changes the log file size to the size you type. If you omit the size parameter, /l displays the current size.
/b	Use with NTFS only. Clears the list of bad clusters on the volume and rescans all allocated and free clusters for errors. /b includes the functionality of /r. Use this parameter after imaging a volume to a new hard disk drive.
/scan	Use with NTFS only. Runs an online scan on the volume.
/forceofflinefix	Use with NTFS only (must be used with /scan). Bypass all online repair; all defects found are queued for offline repair (for example, `chkdsk /spotfix`).
/perf	Use with 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	Use with NTFS only. Runs spot fixing on the volume.
/sdcleanup	Use with NTFS only. Garbage collect unneeded security descriptor data (implies /f).
/offlinescanandfix	Runs an offline scan and fix on the volume.
/freeorphanedchains	Use with FAT/FAT32/exFAT only. Frees any orphaned cluster chains instead of recovering their contents.
/markclean	Use with FAT/FAT32/exFAT only. Marks the volume clean if no corruption was detected, even if /f wasn't specified.
/?	Displays help at the command prompt.

Remarks

The /i or /c switch reduces the amount of time required to run chkdsk by skipping certain volume checks.

If you want chkdsk to correct disk errors, you can't have open files on the drive. If files are open, the following error message appears:

Chkdsk cannot run because the volume is in use by another process. Would you like to schedule this volume to be checked the next time the system restarts? (Y/N)

If you choose to check the drive the next time you restart the computer, chkdsk checks the drive and corrects errors automatically when you restart the computer. If the drive partition is a boot partition, chkdsk automatically restarts the computer after it checks the drive.
You can also use the chkntfs /c command to schedule the volume to be checked the next time the computer is restarted. Use the fsutil dirty set command to set the volume's dirty bit (indicating corruption), so that Windows runs chkdsk when the computer is restarted.
You should use chkdsk occasionally on FAT and NTFS file systems to check for disk errors. Chkdsk examines disk space and disk use and provides a status report specific to each file system. The status report shows errors found in the file system. If you run chkdsk without the /f parameter on an active partition, it might report spurious errors because it can't lock the drive.
Chkdsk corrects logical disk errors only if you specify the /f parameter. Chkdsk must be able to lock the drive to correct errors.

Because repairs on FAT file systems usually change a disk's file allocation table and sometimes cause a loss of data, chkdsk might display a confirmation message similar to the following:
```
10 lost allocation units found in 3 chains.
Convert lost chains to files?
```
- If you press Y, Windows saves each lost chain in the root directory as a file with a name in the format File<nnnn>.chk. When chkdsk finishes, you can check these files to see if they contain any data you need.
- If you press N, Windows fixes the disk, but it doesn't save the contents of the lost allocation units.
If you don't use the /f parameter, chkdsk displays a message that the file needs to be fixed, but it doesn't fix any errors.
If you use chkdsk /f* on a large disk or a disk with a large number of files (for example, millions of files), chkdsk /f might take a long time to complete.
Use the /r parameter to find physical disk errors in the file system and attempt to recover data from any affected disk sectors.
If you specify the /f parameter, chkdsk displays an error message if there are open files on the disk. If you don't specify the /f parameter and open files exist, chkdsk might report lost allocation units on the disk. This could happen if open files haven't yet been recorded in the file allocation table. If chkdsk reports the loss of a large number of allocation units, consider repairing the disk.
Because the Shadow Copies for Shared Folders source volume can't be locked while Shadow Copies for Shared Folders is enabled, running chkdsk against the source volume might report false errors or cause chkdsk to unexpectedly quit. You can, however, check shadow copies for errors by running chkdsk in Read-only mode (without parameters) to check the Shadow Copies for Shared Folders storage volume.
The chkdsk command, with different parameters, is available from the Recovery Console.
On servers that are infrequently restarted, you might want to use the chkntfs or the fsutil dirty query commands to determine whether the volume's dirty bit is already set before running chkdsk.

Physical nature: HDDs use spinning magnetic platters. Sectors and blocks are physically read from the platter.
When chkdsk runs:
- The physical head must move to each data ___location being checked, which is slower due to mechanical movement.
- Checking for bad sectors (with /r) takes longer as every sector's physical integrity is checked and bad ones are replaced if possible.
- High-hour runtimes aren’t uncommon for large drives.

Normally, on large capacity HDDs, /r or /b would take a considerable amount of time as it reads every sector. Even without errors and with a mostly empty drive, the physical read speed bottlenecks the process.

There might be cases where on large capacity HDDs where chkdsk might complete its process too quickly. If this occurs, it might be that:

The volume is mounted dirty or locked by the operating system (OS) or another process.
The chkdsk operation didn't actually scan every sector on the drive.
The HDD might have a failing read head or other hardware issue that causes chkdsk to behave unpredictably.
The chkdsk operation only performed an online scan of the file system structure and wasn't explicitly made to run an offline scan before booting into the OS.

Viewing the chkdsk logs might point to a potential issue during scans. To learn more, see Viewing chkdsk logs.

Physical nature: SSDs store data electronically with no moving parts.
When chkdsk runs:
- No seek time: Reading any sector is equally fast; there’s no mechanical latency.
- Checking for bad sectors (with /r) is faster but still requires reading every single sector. However, NAND flash can read much faster than an HDD can.
- Marking clusters bad is logical, not physical remapping.

As sector reads are faster on SSDs, running the /r and /b parameters complete the process faster due to its physical makeup.

There might be cases where on large capacity SSDs where chkdsk might complete its process too quickly. If this occurs, it might be that:

The chkdsk operation didn't actually scan every sector on the drive.
The SSD didn't have much data to process (more free space).
The SSD scanned is an NVMe that isn’t heavily fragmented.
The SSD might internally optimize "full scans" efficiently, thus further improving scan speed.

Viewing the chkdsk logs might point to a potential issue during scans. To learn more, see Viewing chkdsk logs.

Caution

While running chkdsk on an SSD isn't dangerous, repeated full-surface scans (especially with /r) could unnecessarily increase write/erase cycles, slightly reducing the SSD lifespan. But for occasional checks, this isn't a significant concern.

Understanding exit codes

The following table lists the exit codes that chkdsk reports after it has finished.

Exit code	Description
0	No errors were found.
1	Errors were found and fixed.
2	Performed disk cleanup (such as garbage collection) or didn't perform cleanup because /f was not specified.
3	Could not check the disk, errors could not be fixed, or errors were not fixed because /f was not specified.

Examples

To check the disk in drive D and have Windows fix errors, type:

chkdsk d: /f

If it encounters errors, chkdsk pauses and displays messages. Chkdsk finishes by displaying a report that lists the status of the disk. You can't open any files on the specified drive until chkdsk finishes.

To check all files on a FAT disk in the current directory for noncontiguous blocks, type:

chkdsk *.*

Chkdsk displays a status report, and then lists the files that match the file specifications that have noncontiguous blocks.

Viewing chkdsk logs

There are two methods that can be used to retrieve chkdsk log files in Windows, using the Event Viewer and PowerShell.

Event Viewer
PowerShell

To view logs with Event Viewer, perform the following actions:

Start > Control Panel > Administrative Tools > Event Viewer.

Alternatively, press Win + R keys to bring up the run dialog box, type eventvwr.msc, and select OK.
Expand Windows Logs > right-click on Application > select Filter Current Log.
Within the Filter Current Log window, navigate to Event sources drop-down menu, select Chkdsk and Wininit.
Select OK to finish filtering for these two sources.

There are two source types when retrieving logs in PowerShell, chkdsk and wininit. Run one of the two commands in PowerShell to view the most current chkdsk log:

get-winevent -FilterHashTable @{logname="Application"} | ?{$_.providername -match "chkdsk"} | fl timecreated, message

get-winevent -FilterHashTable @{logname="Application"} | ?{$_.providername -match "wininit"} | fl timecreated, message

To export the log to a specific ___location, add the following to the end of the command | out-file "$env:userprofile\___location\filename.txt". Example:

get-winevent -FilterHashTable @{logname="Application"} | ?{$_.providername -match "chkdsk"} | fl timecreated, message | out-file "C:\Users\Administrator\Desktop\Chkdsk_Log.txt"

get-winevent -FilterHashTable @{logname="Application"} | ?{$_.providername -match "wininit"} | fl timecreated, message | out-file "C:\Users\Administrator\Desktop\Wininit_Log.txt"

Command-Line Syntax Key

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