COMMAND
chkdskCheck and repair a disk volume
chkdsk checks a disk volume's file system for errors and, with /f, repairs them; with /r it also scans for bad sectors and recovers readable data. Because it needs exclusive access, chkdsk on the system drive schedules itself to run at the next restart. Back up important data before running a repair on a failing disk.
Purpose
chkdsk (check disk) verifies the integrity of a volume's file system and, optionally, the physical sectors beneath it. It addresses a different layer from sfc and DISM: those repair Windows' files, chkdsk repairs the file system and media those files live on. It is relevant to boot failures such as inaccessible boot device and file-system stop codes.
Syntax
chkdsk [drive:] [/f] [/r] [/x] [/scan] [/spotfix]Common invocations
Read-only check (safe any time):
chkdsk C:Fix file-system errors (schedules at reboot for the system drive):
chkdsk C: /fFix errors and recover bad sectors (slow; for suspected media damage):
chkdsk C: /rWhen the volume is in use, chkdsk asks to run at the next restart:
Cannot lock current drive.
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)Options
| Option | Effect |
|---|---|
/f | Fix file-system errors |
/r | Locate bad sectors and recover readable data (implies /f) |
/x | Force the volume to dismount first (implies /f) |
/scan | Online scan of NTFS without taking the volume offline |
/spotfix | Fix only specific issues quickly (NTFS) |
On modern NTFS, chkdsk /scan runs while Windows is up and queues any needed fixes for a fast /spotfix at reboot, which is far quicker than a traditional offline repair.
Reading the result
chkdsk reports the stages it ran (file records, indexes, security descriptors, and for /r the free-space and sector scan) and a summary of total disk space and any problems fixed. "Windows has made corrections to the file system" means it repaired something; investigate why (a bad shutdown, a failing drive).
Cautions
- Back up first on a suspect drive. A physically failing disk can deteriorate during a full
/rscan. Image the data, then repair. - SSDs: bad-sector scanning is less meaningful; rely on the drive's SMART health and let TRIM manage the media. Use
/ffor file-system issues, not/rroutinely. - found.### folders hold data chkdsk recovered from broken index entries; check them after a repair.
Common mistakes
- Running
/rroutinely on healthy SSDs, which wastes time and wear. - Interrupting a scheduled reboot scan, which can leave the file system mid-repair.
- Assuming chkdsk fixes Windows corruption. For that, use sfc and DISM.
Frequently asked questions
What is the difference between chkdsk /f and /r?
/f fixes file-system errors (the logical structure). /r implies /f and additionally scans the whole surface for bad sectors, recovering readable data from them, which takes much longer. Use /f for file-system problems and /r when you suspect physical media damage.
Why does chkdsk run at startup?
It needs exclusive access to the volume. The system drive is in use while Windows runs, so chkdsk schedules the repair for the next reboot, before Windows fully loads.
Can chkdsk cause data loss?
Repairs can move corrupted data into found.### folders or, on a physically failing drive, worsen the failure. On a drive you suspect is dying, image or back up the data first, then run chkdsk. On SSDs, prefer the drive's SMART health and TRIM over aggressive surface scans.