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chkdsk Explained: Checking and Repairing a Drive

Intermediate Command Prompt Fixes Applies to: Windows 7, Windows 10, Windows 11

How to check a drive for errors and bad sectors, and what the different chkdsk options actually do.

Before you start: save any open work and note down what you were doing when the problem started — that context helps if you need to search further or ask for help.
  1. Open Command Prompt as administrator, then type chkdsk C: (or your target drive letter) and press Enter to run a read-only check first.
  2. To actually fix errors it finds, use chkdsk C: /f — this requires exclusive access to the drive, so if it's your main system drive, it will ask to schedule the check for your next restart.
  3. For a more thorough scan that also checks for bad sectors, use chkdsk C: /f /r, which takes considerably longer since it physically scans the whole drive surface.
  4. During a scheduled restart check, let it run completely rather than powering off partway through — an interrupted chkdsk can occasionally cause more problems than it solves.
  5. If chkdsk reports a growing number of bad sectors on repeated runs, treat that as a sign the drive itself may be failing and back up your data as a priority.
Still not fixed? Send us the details and we'll help you dig further, or browse related guides in Command Prompt Fixes.

Frequently Asked Questions

Will chkdsk delete any of my files?
No — chkdsk repairs file system errors and can recover data from bad sectors where possible. It doesn't delete personal files as part of its normal operation.
Why does chkdsk need to run on restart sometimes instead of right away?
If you're trying to check the drive Windows is currently running from, it can't be scanned while in use — Windows schedules the check for the next restart instead, before the drive is fully loaded.

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