How To Run System File Checker On Windows 10: A Step-by-Step Guide

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Published on November 10, 2025

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System File Checker (SFC) is a vital utility built into Windows 10 that allows users to scan for and restore corruptions in Windows system files. Damaged or missing system files can lead to a wide range of problems, from minor glitches to complete system instability. Knowing how to run System File Checker can be a lifesaver when troubleshooting Windows issues.

This guide provides a comprehensive, step-by-step walkthrough on how to effectively use the System File Checker tool in Windows 10. By following these instructions, you can diagnose and repair potentially critical system file errors, ensuring the stability and performance of your operating system.

How Do I Run System File Checker on Windows 10?

Preparing to Run System File Checker

Before initiating the scan, it’s good practice to close any open applications and save your work. While SFC is generally safe, unexpected issues can sometimes arise. Running the scan from an elevated Command Prompt ensures that the tool has the necessary permissions to make changes.

Close all open applications and save your work.
Open the Start Menu.
Type “cmd”.
Right-click on “Command Prompt” in the search results.
Select “Run as administrator”.
Click “Yes” if prompted by User Account Control.

Running the SFC Scan

The core command to initiate the System File Checker scan is sfc /scannow. This command instructs SFC to scan all protected system files and replace corrupted files with a cached copy located in a compressed folder at %WinDir%\System32\dllcache.

In the elevated Command Prompt window, type sfc /scannow and press Enter.
Wait for the scan to complete. This process can take some time, often 15-30 minutes, depending on the speed of your system and the extent of the damage.
Do not close the Command Prompt window during the scan.
Observe the results displayed in the Command Prompt window once the scan is complete.

Interpreting the SFC Scan Results

After the scan completes, SFC will display one of several messages. Understanding these messages is crucial for determining the next steps.

“Windows Resource Protection did not find any integrity violations.” This means that SFC did not detect any corrupted system files. No further action is required.
“Windows Resource Protection found corrupt files and successfully repaired them.” This indicates that SFC found and successfully replaced corrupted system files. You should restart your computer to ensure the changes take effect.
“Windows Resource Protection found corrupt files but was unable to fix some of them.” This means that SFC found corrupted files but could not repair all of them. In this case, you’ll need to examine the CBS.log file to identify the problematic files and attempt manual repair or use the DISM tool.

Using DISM to Repair the Windows Image

If SFC cannot repair the corrupted files, the Deployment Image Servicing and Management (DISM) tool can be used to repair the underlying Windows image.

In the elevated Command Prompt window, type the following command and press Enter: DISM /Online /Cleanup-Image /RestoreHealth
Wait for the DISM process to complete. This can also take a significant amount of time.
After DISM completes, run the sfc /scannow command again.
Restart your computer after the SFC scan completes.

Analyzing the CBS.log File

If SFC is unable to repair some files, the CBS.log file contains detailed information about the scan and repair process. Analyzing this log can help identify the specific files that could not be repaired.

Open File Explorer.
Navigate to C:\Windows\Logs\CBS.
Open the CBS.log file with a text editor like Notepad.
Search for entries related to the SFC scan, typically marked with “SR” or “Repair”.
Identify the files that SFC could not repair.
Attempt to manually replace these files with known good copies from a working Windows installation or installation media.

Tips for Successful SFC Scans

Ensure your system has sufficient free disk space. SFC requires space to create temporary files and backups.
Disable any antivirus software temporarily. Antivirus programs can sometimes interfere with the SFC scan.
Run SFC in Safe Mode. This can help if other programs are interfering with the scan.
If you continue to experience problems, consider performing a clean installation of Windows.

Comparing SFC and DISM

Feature	System File Checker (SFC)	DISM (Deployment Image Servicing and Management)
Purpose	Scans and repairs protected system files.	Repairs the Windows image, which is the source for system files.
Repair Source	Uses a cached copy of system files in the dllcache folder.	Downloads replacement files from Windows Update or uses a local installation source.
Use Case	Repairing individual corrupted system files.	Repairing the underlying Windows image when SFC cannot fix issues.
Command	`sfc /scannow`	`DISM /Online /Cleanup-Image /RestoreHealth`

Restoring Windows Stability

Running System File Checker is a crucial step in maintaining a healthy and stable Windows 10 system. By proactively addressing corrupted system files, you can prevent a wide range of issues and ensure your computer runs smoothly.

FAQ

Can I run SFC in Safe Mode? Yes, running SFC in Safe Mode can be helpful if other programs are interfering with the scan.

How long does the SFC scan take? The scan can take anywhere from 15 to 30 minutes, or even longer, depending on the speed of your system and the extent of the damage.

What does it mean if SFC finds corrupt files but can’t fix them? It means that the underlying Windows image may be damaged. You should use the DISM tool to repair the image and then run SFC again.

Is it safe to disable my antivirus software before running SFC? Temporarily disabling your antivirus software can prevent it from interfering with the SFC scan, but remember to re-enable it afterward.

Where can I find the CBS.log file? The CBS.log file is located in the C:\Windows\Logs\CBS directory.