sfc

Scans and verifies the integrity of all protected system files and replaces incorrect versions with correct versions. If this command discovers that a protected file has been overwritten, it retrieves the correct version of the file from the systemroot\ folder, and then replaces the incorrect file.

Important

You must be logged on as a member of the Administrators group to run this command.

Syntax

sfc [/scannow] [/verifyonly] [/scanfile=<file>] [/verifyfile=<file>] [/offwindir=<offline windows directory> /offbootdir=<offline boot directory> /offlogfile=<log file path>]

Parameters

Parameter Description
/scannow Scans the integrity of all protected system files and repairs files with problems when possible.
/verifyonly Scans the integrity of all protected system files, without performing repairs.
/scanfile <file> Scans the integrity of the specified file (full path and filename) and attempts to repair any problems if they're detected.
/verifyfile <file> Verifies the integrity of the specified file (full path and filename), without performing repairs.
/offwindir <offline windows directory> Specifies the location of the offline windows directory, for offline repair.
/offbootdir <offline boot directory> Specifies the location of the offline boot directory for offline repair.
/offlogfile=<log file path> Specifies a location to store the log file other than the default.
/? Displays help at the command prompt.

Examples

To verify the kernel32.dll file, type:

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

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

sfc /scanfile=D:\windows\system32\kernel32.dll /offbootdir=D:\ /offwindir=d:\windows