Inbuilt scanner in system

Our system has the inbuilt scanner for checking files. This is done by not installing any software
The various command line options are
Go to cmd prompt and type any of the following keeping the prefix as sfc

sfc [/scannow] [/scanonce] [/scanboot] [/revert] [/purgecache] [/cachesize=x]

/scannow - Scans all protected system files immediately.
/scanonce - Scans all protected system files once.
/scanboot - Scans all protected system files every time the computer is restarted.
/revert - Returns the scan to its default operation.
/purgecache - Purges the Windows File Protection file cache and scans all protected system files immediately.
/cachesize=x - Sets the size, in MB, of the Windows File Protection file cache.