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22 January 2024  Amanda J. Brook  Senior Product Manager
 

Summary
Learn how to use the SFC command to repair system failures in Windows. Also, transfer or recover important data without entering the Windows system to avoid file loss.



Table of contents

table iconI. About SFC commands
table iconII. When unable to enter the system, use Renee PassNow to transfer or recover data
SFC command

I. About SFC commands

1. Definition, function and parameters of SFC command

SFC (System File Checker) is a built-in utility in Windows that is highly recommended for troubleshooting. This powerful tool scans and verifies the integrity of all protected system files, replacing any incorrect versions with the correct ones. To utilize this command, simply log in to Windows as an Administrator.
The SFC command contains several parameters. If you want to view the details of the SFC parameters in the computer, you can run the (sfc /?) command in the command prompt to learn the detailed introduction of the SFC command parameters.
The parameters and specific instructions of the SFC command are as follows:

parameter

illustrate

How to enter in command prompt

/scannow

Scans the integrity of all protected system files and repairs files containing problems where possible.

sfc /scannow

/verifyonly

Scans the integrity of all protected system files without performing repairs.

sfc /verifyonly

/scanfile <file>

Scans the specified file for integrity (full path and filename) and attempts to repair any problems detected.

sfc /scanfile=<file>

Note: <file> needs to be replaced with the full path and file name, such as sfc /scanfile=c:\windows\system32\kernel32.dll

/verifyfile <file>

Verify the integrity (full path and filename) of the specified file without performing repairs.

sfc /verifyfile=<file>

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

/offwindir <offline windows directory>

Specifies the location of the offline Windows directory for offline repair.

sfc /offwindir=<offline windows directory>

Example: sfc /scannow /offbootdir=D:\ /offwindir=D:\windows

/offbootdir <offline boot directory>

Specifies the location of the offline boot directory for offline repair.

sfc /offbootdir=<offline boot directory>

Example: sfc /scannow /offbootdir=D:\ /offwindir=D:\windows

/?

Display help at the command prompt.

sfc /?

2. How to run SFC command?

①When the system can be accessed normally
Step 1: Run the computer and log in to Windows with an administrator account. Enter (cmd) in the search box on the left side of the taskbar, then right-click (Command Prompt) in the search results and select (Run as administrator).
run as administrator
Step 2: Then enter the SFC command in the command prompt as required and press the (Enter) key.
(sfc /scannow) is a more commonly used command that can scan the integrity of all protected system files and repair problematic files.

Note that if you are using Windows 10, Windows 8.1 or Windows 8, before running the SFC command to repair missing or damaged system files, please run the (DISM.exe /Online /Cleanup-image /Restorehealth) command , and then run (sfc /scannow). If the prompt “Windows Resource Protection cannot perform the requested operation” appears after running (sfc /scannow), please click here for details.

run DISM command
Check and fix system files Windows 10
②When the system cannot be accessed normally
Step 1: Press the power button to turn on your computer. When the startup logo appears, hold down the power button to force a shutdown. Repeat this process three times to allow the computer to fully start up. Then, on the “Auto Repair” interface, select the “advanced option” to enter the Windows recovery environment. Alternatively, you can use a Windows installation disk to start the computer. Simply set the disk as the first option in the boot sequence in the BIOS settings, save the changes, and restart the computer. Once it restarts, select the “Repair you computer” option on the “Install Now” interface to enter the recovery environment.
windows installation repair your computer
Step 2: After entering the recovery environment, navigate to (Troubleshoot)>(Advanced Options)>(Command Prompt).
command prompt
Step 3: In the opened command prompt window, enter the SFC command as required, such as (sfc /scannow /offbootdir=D:\ /offwindir=D:\windows), and press the (Enter) key. The scan may take approximately 5-20 minutes to complete. After the scan is complete, remove the Windows installation disk and restart the computer to see if the problem is resolved.
Note: (/scannow) in the (sfc /scannow /offbootdir=D:\ /offwindir=D:\windows) command can be used to scan the integrity of system files and repair problematic files. The (/offbootdir) parameter specifies the location of the offline boot directory for repair, while the (/offwindir) parameter specifies the location of the offline Windows directory for repair. The values for (D:\) in (/offbootdir=D:\) and (/offwindir=D:\windows) can be adjusted as needed.
Run sfc /scannow /offbootdir=D: /offwindir=D:windows
The above is the introduction of the SFC command. When the system fails and cannot be accessed normally, in order to avoid data loss in the computer, you can refer to the second part to learn how to transfer or restore data without entering Windows.

II. When unable to enter the system, use Renee PassNow to transfer or recover data

1. What is Renee PassNow?

Renee PassNow is a professional system rescue software, which can help Windows users clear Windows account passwords, create new administrator accounts; restore disk/memory card data, recover data after hard disk formatting; transfer disk files; erase or scan Disk files, etc. In addition, this software also supports repairing Windows system problems, such as: repairing MBR boot records, DBR error parameters, 0xc00000e, Windows system startup failure, and some problems that cause black screen or blue screen, etc. As a system rescue tool with various functions, it is perfectly compatible with multiple systems including Windows 10/8.1/8/7/XP/Vista, and can meet the system rescue needs of different users.
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2. How to use Renee PassNow to transfer or recover data?

Step 1: Download and install Renee PassNow on another computer that can log in and run normally, then connect the USB disk to the PC.
Please select the (Create a Live USB) option under “Step 1: Select creation method” in the main interface.

Note: Before performing this operation, please make sure that the important files in the USB disk have been saved in other locations because the operation will delete all the data in the USB disk.

create a boot media with renee passnow
Step 2: Next, choose the appropriate system type (x64 or x86) and select the “Download Now” button to obtain the ISO file. Once the download is complete, click the “Create USB” button to initiate the process, and then eject the USB by clicking the “Eject USB” button.
use renee passnow to create usb to reset passnword
Step 3: Connect the boot device you have created to the computer where you want to transfer data. Turn on the computer and a shortcut key will appear on the screen to enter the BIOS (this interface may only appear for a few seconds). Continuously click the BIOS shortcut key to access the BIOS settings. From there, set the boot USB as the first option in the boot sequence under Boot Priority. Save the changes and restart the computer.
select boot order
Step 4: Choose the option “Data Transfer”. If you wish to transfer all the data from your hard disk, simply select the “Data Backup” option.
Note: If you lack administrator privileges on your current account and need to access the command prompt as an administrator, you can utilize the “Create New User” function in Renee PassNow to establish a new administrator account.
data transfer
Step 5: You can simply click on each disk drive letter (C/D/E/F, etc.) to check for any potential loss of important files. If there are no missing files, it is highly recommended that you transfer them to an external disk for safekeeping. The process of transferring data is straightforward and effortless. For instance, if you wish to transfer data from the C drive to the G drive, you can easily select the C drive on the upper left, then choose the G drive on the upper right, and finally select the desired files from the C drive. Once selected, click on the Copy function button in the middle to easily transfer the disk data. In case you want to delete a file, you can simply select it and click on the (Delete) button in the middle. However, please note that this action cannot be undone, so proceed with caution.
data transfer in Renee Passnow
Step 6: If you find that there is data loss, please select the (Undeleter) option on the main interface of the function, and click the (Run) button.
data recovery function in Renee Passnow
Step 7: Select (Whole Disk Scan) to scan the target hard disk.
select whole disk scan in renee undeleter
Step 8: After the scan is complete, choose the file you want to recover and click the “Recover” button to start the data recovery. Save the file to an external disk and eject the USB disk once the recovery is finished.
recover files from whole disk scan with renee undeleter