author avatar
4 January 2021  Ashley S. Miller  Specialist of Customer Service Dept.
 

Summary
The sfc /scannow is a command that instructs to scan for protected Windows system files and automatically restore corrupted system files. Read this article and use sfc /scannow command line to scan and restore corruptions in Windows 10 system files easily.



Use SFC command

About SFC

System File Checker (SFC) is a utility in Windows. It can scan all protected system files and check the integrality of them. If it finds issues with any of these protected files, it will replace it.

Sfc Command Syntax

sfc /scannow: This option aims to scan all protected operating system files and repair the corrupted files.

sfc /verifyonly: This option is also used to scan all protected operating system files but not restore.

sfc /scanfile: This option is also used to scan all protected operating system and repair the corrupted files with full path.

sfc /verifyfile: This option is used to verify the files with full path but without repairing.

sfc /offbootdir: This option is used to define the boot directory when using sfc offline.

sfc /offwindir： This option is used to define the Windows directory when using sfc offline.

sfc /logfile: This option is used to define log files and selectively enable logging when using sfc offline.

sfc command

How Does SFC /Scannow Work?

The sfc /scannow is one of the common options in sfc command. It can scan all protected operating system files and repair the corruptions. If your system files are damaged or missing, it’s suggested to use the sfc /scannow option to fix them at first.
sfc /scannow Windows 10
Besides, the sfc /scannow is different from system restore. The sfc /scannow option instructs to replace the corrupted system files with new and complete files, which will not influence the system and just modify the system files.

How to Repair Windows 10 System Files Using SFC /Scannow?

Note: It’s suggested to backup or transfer your important data before performing this command. Additionally, it requires an administrator account to perform. If you don’t have it, please contact administrator. Or use Renee PassNow to quickly create an administrator account.

Create Administrator Account with Renee PassNow Beforehand

Step 1: Download and install Renee PassNow in any workable Windows computer. 

press to the download button

Step 2: Choose creation method, USB or CD/DVD.

Select one option from [Crate a Live USB] and [Create a Live CD]. Then, select [x64] or [x86] according to your computer. Next, click on [Download Now] to download the licensed ISO. Remember to activate the software beforehand. After that, click on [Create USB] to create the boot media.
use renee passnow to create usb to reset passnword

Step 3: Boot the target PC from the created password reset USB/CD/DVD.

You will boot the target computer via a new created reset disk. Firstly, please hold a hot key to enter the BIOS menu and put CD-ROM or Removable Devices as the first choice. Please click here to know about how to change the boot order of your computer. After changing it successfully, please remember to save your setting and then restart your PC.

steps to change the boot order in BIOS

Step 4: Select “PassNow!”.

Reset password

Step 5: Click “Create new account”.

The created administrator account named “Reneelab” with administrator rights, and its default password is “123456789”. You are able to change the password of target account with this new created administrator.

Create new account
Besides, Renee PassNow also provides data transfer, data recovery, hard disk scan, Windows password reset, etc.

Run SFC /Scannow When Windows 10 Boots Normally

Step 1: Type “cmd” in search box, right click “Command Prompt” and select “Run as administrator”.
run cmd
Step 2: When command prompt pops up, type in: sfc /scannow. Press “Enter”.
Check and fix system files Windows 10
Step 3: Next, system file checker starts to scan and repair the corruptions in system. Restart the PC once the repair process completes.
Tips: When you type in sfc /scannow, please note that there is a space between sfc and /scannow. Besides, performing this command may take some time. Please wait patiently.

Run SFC /Scannow When Windows 10 Can’t Boot Normally

Note: This way requires Windows installation disk. If you don’t have it, please refer to the solution to create Windows installation disk.
Step 1: Connect Windows installation disk to the computer. Then start the computer.
connect usb to laptop
Step 2: In BIOS setup, change the boot order. Put “Removable Devices” as the first boot order.
change boot order in BIOS menu
Step 3: Boot the PC from USB disk. Click “Repair Your Computer” in the bottom-left corner after you enter Windows installation screen.
Repair your computer
Step 4: When you enter Windows Recovery Environment, select “Troubleshoot” > “Advanced Options” > “Command Prompt”.
command prompt
Step 5: Once Command Prompt pops up, type in: sfc /scannow. Press “Enter”.
Check and fix system files Windows 10
You will see a message “Windows Resource Protection did not find any integrity violation” if your operating system files are not corrupted or missing,
Step 6: Restart the PC after the scan and repair process finishes.