SFC is a utility tool, and its scannow option is not the only option it offers. While the scannow option resolves most issues, there are a few other commands or modifiers that also SFC offers, and you can learn about them below: scannow – This scans all the Windows system files and replaces corrupted or incorrect files with new ones. scanonce – This one scans all the system files at once. scanboot – This command scans all the system files at boot each time the system is restarted. cancel – Using this command cancels all the pending scans. enable – It will enable Windows File Protection (WFP). Once enabled, it will prevent programs from modifying Windows system files.