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    Specialist of Customer Service Dept.


Many people have vague idea about “System File Checker”. So, what is System File Checker? How does it work? What is it used for? You may get it in the essay.

1. What is System File Checker?

System File Checker, SFC for short, is a utility tool of Microsoft Windows. Users can scan all protected system files and check the file integrity with this tool, and then fix or recover those damaged Windows system files. SFC commands are useful in system file maintenance. Let us see the orders and functions in System File Checkers (SFC).
Administrator command prompt

Commands and Functions of System File Checker



sfc /scannowImmediately scan the integrity of all protected system files and recover as mush as possible.
sfc /scanonceScan the integrity of all protected system files in the next start and recover as much as possible.
sfc /scanbootScan the integrity of all protected system files in each start and recover as much as possible.
sfc /purgecacheClear file cache and scan all protected system files. (It is used to free disk space when system disk space is not enough.)
sfc / verifyonlyImmediately scan the integrity of all protected system files but does not recoverr.
sfc /scanfileScan the integrity of the cited files; if any problem, recover them (the complete path is necessary).
sfc /verifyfileCheck the integrity of files with complete paths, no recovery step included.
sfc /offbootdirAssign the position of the offline start directory in offline recovery.
sfc /offwindirAssign the position of offline Windows directory for offline recovery.
sfc /offlogfileOptionally enable logging through the designated path of the log files in offline recovery.
sfc /cancelStop scanning all stopped, protected system files.
sfc /enableEnable Windows file protection for normal operation.
sfc /quietSilently replace all incorrect system file versions.
sfc /cachesize=xSet the file cache size.
Notice: If you never use sfc /offwindir and sfc /offbootdir to assign the setup directory, you should run the recover online when you want to use sfc commands to recover Windows.

2. How to Use System File Checker in Windows 10/7 to Check and Recover System Files?

Notice: The commands of running System File Checker are carried out under the administrator account. Please connect the administrator or create a new administrator account, if you haven’t had any administrator privilege. Here it is recommended to try Renee Passnow, a third-party software which can hep you create administrator account.
Renee PassNow can not only create a new administrator account but also many Windows problems, such as resetting any Windows password, transferring important files, recovering Windows abnormal startup and recovering dismissed data in the damaged Windows system.

Create Administrator Account with Renee Passnow

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

press to the download button

Step 2: Open the software. 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” to create a new administrator to quickly access your PC.

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

Run System File Checker to Recover System Files

You can run System File Checker to recover system files when you’ve created your administrator account. In this following, it is introduced a method that you can run System File Checker in Windows 10 or other Windows version to recover damaged or missed system files when you have access or no access to the system.

System Starts as Usual

① Search [Command Prompt] in the task search bar; then right click [Command Prompt] to select [Run as Administrator].
run command prompt as administrator in start menu
② Open the command prompt box; input [sfc/scannow] and Press Enter to run.
enter sfc scannow
③ Next, System File Checker will scan system files automatically and recover all defective system files.
④ It takes some time to execute the command, please wait patiently. Restart the computer when the recover is finished.
command prompt scan completed
If system fails to start, please try to get into safe mode (Press F8 in Windows 7 or below; or in Windows 8/10, refer to the method 2 in “Enter Safe Mode in Windows 10”.) Then, get to the command prompt and run System File Checker to recover system files. However, if you are not able to enter into safe mode, check the method as follows.

System Fails to Boot

Notice: A Windows setup disk is required in this method. Please refer to method 2 in “How to Make Windows Boot Disk (USB Drive Supported)” , if you don’t have a Windows installation disk.
① Connect the Windows setup USB to computer, then start the computer.
connect usb to laptop
② Enter BIOS and set the system to boot from the Windows installation disk.
change boot order
③ Click [Repair your computer] in the lower left of the setup interface.
Repair your computer
④ Enter Windows Recovery Environment, select [Troubleshoot] > [Advanced Options] > [Command Prompt].
select command prompt in advanced option
⑤ Enter [sfc/scannow] in the command prompt window and press Enter to run.
enter sfc scannow
⑥ Restart the computer when System File Checker has scanned and recovered the system files.
command prompt scan completed