Akorat když přidám za to sfc /scannow ješte tečku takže (sfc /scannow.) tak mi napíše

Microsoft (R) Windows (R) Resource Checker Version 6.0
Copyright (C) Microsoft Corporation. All rights reserved.

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

SFC [/SCANNOW] [/VERIFYONLY] [/SCANFILE=<file>] [/VERIFYFILE=<file>]
[/OFFWINDIR=<offline windows directory> /OFFBOOTDIR=<offline boot directory> [/OFFLOGFILE=<log file path>]]

/SCANNOW Scans 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 referenced file, repairs file if problems are
identified. Specify full path <file>
/VERIFYFILE Verifies the integrity of the file with full path <file>. No repair
operation is performed.
/OFFBOOTDIR For offline repair, specify the location of the offline boot directory
/OFFWINDIR For offline repair, specify the location of the offline windows directory
/OFFLOGFILE For offline repair, optionally enable logging by specifying a log file path

e.g.

sfc /SCANNOW
sfc /VERIFYFILE=c:\windows\system32\kernel32.dll
sfc /SCANFILE=d:\windows\system32\kernel32.dll /OFFBOOTDIR=d:\ /OFFWINDIR=d:\windows
sfc /SCANFILE=d:\windows\system32\kernel32.dll /OFFBOOTDIR=d:\ /OFFWINDIR=d:\windows /OFFLOGFILE=c:\log.txt
sfc /VERIFYONLY