CHKDSK /F vs /R: Which Switch Should You Use?
Download nowThe /f and /r switches are the two most-used chkdsk options, and people often confuse them. /f fixes logical file system errors; /r does that plus a physical bad-sector scan.
Updated August 9, 2026 · PC Utility Hub Editorial Team
chkdsk /f: fix file system errors
chkdsk C: /f repairs problems in the file system's own bookkeeping — corrupted directory entries, incorrect cluster chain links, orphaned files. It does not examine the physical disk surface, so it runs faster than /r. Use /f after an improper shutdown or when Windows reports 'file system corruption' or dirty bit warnings.
chkdsk /r: fix errors and scan for bad sectors
chkdsk C: /r does everything /f does, plus it reads every sector on the volume, tries to recover data from unreadable sectors, and marks bad sectors so the file system stops using them. This takes much longer — potentially hours on large mechanical drives — because it physically reads the entire disk.
/r automatically includes /f, so you never need to combine them as separate passes; running chkdsk C: /f /r is redundant but harmless.
Side-by-side comparison
| Aspect | /f | /r |
|---|---|---|
| Checks file system structure | Yes | Yes |
| Scans physical sectors | No | Yes |
| Speed | Faster | Much slower |
| Typical use case | After crash/dirty shutdown | Suspected bad sectors, drive errors, SMART warnings |
| Requires reboot on system drive | Usually | Usually |
Which one should you run first?
If you're not sure of the problem, start with chkdsk C: /f. If errors persist, drive access is slow, or you see SMART warnings or read errors in Event Viewer, follow up with chkdsk C: /r for the deeper scan.
Frequently asked questions
- Does /r include /f automatically?
- Yes. Running /r always performs the /f repairs as well; there's no need to run them separately.
- Which switch takes longer?
- /r is significantly slower because it reads the entire physical disk surface, not just the file system metadata.
- Can /r fix a failing hard drive?
- It can mark bad sectors so they're no longer used, but it can't reverse mechanical or electronic drive failure. If bad sectors keep increasing, back up data and replace the drive.
Related pages
- CHKDSKOverview of the chkdsk utility, its switches, and how it fits into Windows disk maintenance.
- Run CHKDSK in Windows 11Two ways to launch chkdsk in Windows 11 and how to interpret the scan.
- CHKDSK RepairStep-by-step chkdsk repair workflow for a corrupted internal or external drive.
- File Recovery ToolsHow file/data recovery utilities work on Windows and how to choose one.