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Repair System Files With sfc /scannow

Scan protected Windows files and restore corrupted copies.

WindowssystemadminpowershellDiagnosticsLow risk
Run sfc /scannow from an elevated prompt to scan and repair system files.

01Command

Command
$ sfc /scannow

02What it does

System File Checker compares protected files against a cached copy and replaces corrupt ones, resolving many puzzling crashes and update failures. It is a console tool by design and is often scripted as the first step of a repair workflow.

03Risk

RiskLow risk
RequirementsRun from an elevated Command Prompt
!Warning: Repairs may need Windows installation media or a network source; take a restore point first on production machines.

04Undo

✓No undo needed — this command does not change persistent state.

05Sources

  • sfc
    Microsoft Learn · vendor-doc · 2026-09-20
    Evidence: Scans and repairs protected system files with System File Checker.

Last verified: 2026-10-13 · Category: System & Settings

06Related solutions

Scan and repair Windows system files with SFC
WindowssystemTerminalDiagnostics

Use the System File Checker to verify every protected Windows system file against known-good copies and automatically replace the damaged ones.

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Check a drive for file system errors with chkdsk
WindowsFilessystemDiagnostics

Diagnose NTFS file system errors and bad sectors on any volume — including the system drive while Windows is running — before committing to a repair.

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Repair the Windows component store with DISM RestoreHealth
WindowssystemTerminalDiagnostics

Use the Deployment Image Servicing and Management tool to detect and repair corruption in the Windows component store, the layer SFC depends on.

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