Applies To: Windows Vista,Windows Server 2008 R2 with SP1,Windows Server 2008 R2,Windows Server 2008

Scans and verifies the integrity of all protected system files and replaces incorrect versions with correct versions.

For examples of how to use this command, see Examples.

Syntax

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Sfc [/SCANNOW] [/VERIFYONLY] [/SCANFILE=<file>] [/VERIFYFILE=<file>] [/OFFWINDIR=<offline windows directory> /OFFBOOTDIR=<offline boot directory>]

Parameters

Parameter Description

/SCANNOW

Scans the integrity of all protected system files and repairs files with problems when possible.

/VERIFYONLY

Scans integrity of all protected system files. No repair operation is performed.

/SCANFILE

Scans integrity of the specified file and repairs the file if problems are detected, when possible.

<file>

Specified full path and filename

/VERIFYFILE

Verifies the integrity of the specified file. No repair operation is performed.

/OFFWINDIR

Specifies the location of the offline windows directory, for offline repair.

/OFFBOOTDIR

Specifies the location of the offline boot directory for offline

Remarks

  • You must be logged on as a member of the Administrators group to run sfc.exe.

  • If sfc discovers that a protected file has been overwritten, it retrieves the correct version of the file from the systemroot\system32\dllcache folder, and then replaces the incorrect file.

  • There are functional differences between sfc on Windows ServerŽ 2003, Windows ServerŽ 2008, and Windows ServerŽ 2008 R2:

    • For more information about sfc on Windows Server 2003, see System File Checker (sfc).

Examples

To verify the kernel32.dll file, type:

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sfc /VERIFYFILE=c:\windows\system32\kernel32.dll

To setup offline repair of the kernel32.dll file with an offline boot directory set to d: and offline windows directory set to d:\windows, type:

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sfc /SCANFILE=d:\windows\system32\kernel32.dll /OFFBOOTDIR=d:\ /OFFWINDI R=d:\windows

Additional references