How to Use System File Checker in Windows 11

October 18, 2025

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Windows 11 is a powerful and modern operating system, but like any other OS, it can face performance issues due to corrupted or missing system files. Sometimes, you may notice strange system errors, apps crashing unexpectedly, or even Windows failing to boot properly. In such cases, System File Checker (SFC) becomes an essential tool.

The SFC command is a built-in utility in Windows 11 that scans protected system files and automatically replaces damaged or missing ones with cached versions stored in the system. This tool can help restore stability and prevent further system damage.

In this guide, you’ll learn how to use the System File Checker tool in Windows 11 step by step. We’ll also cover how it works, when to use it, and what to do if it doesn’t fix your problem. Let’s begin with the basics.

What Is the System File Checker (SFC) Tool?

The System File Checker (SFC) is a built-in Windows command-line tool that scans all protected system files on your computer and verifies their integrity. If it detects that a file is corrupted, modified, or missing, it replaces it with a correct version from the Windows Component Store located in the WinSxS folder.

The SFC tool has existed since Windows XP and remains a crucial repair utility in Windows 11. It helps fix many issues, such as:

Missing or damaged system DLL files
Corrupted drivers or configuration files
Windows startup errors
Problems after malware infections

In short, SFC /scannow is one of the easiest ways to repair system-level issues without reinstalling Windows. It runs directly from Command Prompt or Windows PowerShell, requiring administrative privileges.

When Should You Run SFC in Windows 11?

You don’t need to run SFC every day. It’s best used when you experience certain problems that indicate file corruption. Here are some common scenarios where running SFC can help:

Your PC freezes or crashes frequently.
Some Windows features, like File Explorer or Start Menu, stop working.
Windows updates fail to install properly.
Blue Screen of Death (BSOD) errors occur randomly.
After malware removal, system files behave abnormally.
Error messages like “Windows Resource Protection found corrupt files but was unable to fix some of them.”

If you notice these symptoms, running the SFC /scannow command can often restore normal performance.

For best results, it’s also recommended to run the DISM tool before using SFC. The DISM command repairs the Windows image itself, ensuring SFC has a healthy reference point to replace corrupted files.

How to Run the System File Checker (SFC) Tool in Windows 11

Let’s go step by step through how to use the SFC tool correctly.

Step 1: Open Command Prompt as Administrator

To use SFC, you must run the command with administrative rights. Follow these steps:

Press Windows + S and type cmd.
Right-click Command Prompt and select Run as administrator.
Click Yes if prompted by User Account Control (UAC).

Alternatively, you can use Windows Terminal or PowerShell with admin privileges:

Press Windows + X and select Windows Terminal (Admin) or PowerShell (Admin).

Once the terminal window opens, you’re ready to enter the command that will scan your system files.

Step 2: Run the SFC /scannow Command

Type the following command and press Enter:

sfc /scannow

This command tells Windows to begin scanning all protected system files. The process usually takes 10 to 20 minutes, depending on your system speed and storage type (SSD or HDD).

While it runs, you’ll see a progress percentage on-screen. It’s important not to close the Command Prompt during the process. Once completed, you’ll receive a message indicating the result of the scan.

Understanding the SFC Scan Results

After the scan completes, Windows will display one of several messages. Here’s what they mean:

Windows Resource Protection did not find any integrity violations.
→ No system files were missing or corrupted.
Windows Resource Protection found corrupt files and successfully repaired them.
→ The tool fixed all detected problems automatically.
Windows Resource Protection found corrupt files but was unable to fix some of them.
→ SFC found issues but couldn’t repair them. You’ll need to run DISM before retrying.
Windows Resource Protection could not perform the requested operation.
→ There might be a deeper issue with Windows or a problem accessing certain files. Try running the scan in Safe Mode.

If SFC cannot repair files, move to the next section to use the Deployment Image Servicing and Management (DISM) tool.

Using DISM Before Running SFC

If SFC fails to repair your system files, use the DISM tool to fix the underlying Windows image. The Deployment Image Servicing and Management (DISM) command checks the health of your Windows image and downloads fresh copies of corrupted files from Windows Update.

Here’s how to do it:

Open Command Prompt (Admin).
Run these commands one by one:

DISM /Online /Cleanup-Image /CheckHealth
DISM /Online /Cleanup-Image /ScanHealth
DISM /Online /Cleanup-Image /RestoreHealth

The /CheckHealth command checks for corruption.
/ScanHealth performs a deeper scan, and /RestoreHealth repairs the issues.

After DISM completes, you should see the message “The restore operation completed successfully.”
Now, run SFC again using:

sfc /scannow

This time, the tool should be able to repair the remaining corrupted files.

Running DISM before SFC ensures the integrity of your Windows image, making SFC more effective in fixing protected system files.

Running SFC in Safe Mode

Sometimes, Windows cannot fix files when the system is running normally because certain files are in use. In such cases, running SFC in Safe Mode can help.

Here’s how to do it:

Press Windows + I to open Settings.
Go to System > Recovery.
Under Advanced startup, click Restart now.
When your PC restarts, go to Troubleshoot > Advanced options > Startup Settings > Restart.
After reboot, press 4 or F4 to enter Safe Mode.

Now open Command Prompt as Administrator and run:

sfc /scannow

Running the command in Safe Mode allows SFC to access and replace files that may be locked during normal operation.

How to View the SFC Log File

If SFC reports that it repaired some files or couldn’t fix others, you can view detailed logs to identify the exact files affected.

Open Command Prompt (Admin).
Type the following command:

findstr /c:"[SR]" %windir%\Logs\CBS\CBS.log > "%userprofile%\Desktop\SFC_Details.txt"

This command extracts all System File Checker entries from the CBS.log file and saves them as SFC_Details.txt on your desktop.

You can open this text file to check:

Which files were scanned
Which files were repaired
Which files couldn’t be repaired

This log can help you manually replace specific corrupted files if needed.

Alternative Ways to Run SFC

You can also run the System File Checker from other environments, such as:

Windows Recovery Environment (WinRE):
Boot into recovery mode and open Command Prompt from Advanced Options. Then run: sfc /scannow /offbootdir=C:\ /offwindir=C:\Windows
Windows PowerShell:
Launch PowerShell as administrator and type: sfc /scannow

Running SFC from these environments can help if Windows cannot start normally or if SFC fails to complete in standard mode.

Tips to Get the Best Results

Always run SFC as an administrator.
Disconnect external drives to avoid false corruption reports.
Run DISM first if you get errors like “Windows Resource Protection could not perform the requested operation.”
Ensure your Windows Update is enabled, as DISM may download files from it.
Avoid using your PC while the scan is running.

These small precautions make the SFC scan faster and more reliable.

Common Errors and Fixes

Here are some common problems users face when using SFC and how to fix them:

SFC /scannow stuck at 0% or 100%:

Restart your computer and try again in Safe Mode.

SFC cannot repair corrupted files:

Run DISM /RestoreHealth before rerunning SFC.

Windows Resource Protection could not perform the requested operation:

Boot into Safe Mode and execute the SFC command.

Access denied errors:

Ensure you run the Command Prompt with administrator privileges.

CBS.log file missing:

Check %windir%\Logs\CBS manually or rerun the scan.

Following these troubleshooting steps should help fix any errors during your SFC process.

Final Thoughts

The System File Checker (SFC) tool in Windows 11 is one of the simplest yet most effective ways to repair corrupted or missing system files. Whether your PC is crashing, behaving slowly, or displaying errors, running sfc /scannow can often bring it back to normal.

If SFC doesn’t fix your problem the first time, using the DISM tool before rerunning it usually resolves most system file issues. For deeper problems, consider running the scan in Safe Mode or using recovery mode.

Keeping your Windows installation healthy with SFC and DISM ensures stability, better performance, and fewer unexpected crashes — all without reinstalling Windows.

By learning to use this tool effectively, you can save hours of troubleshooting time and keep your Windows 11 system running smoothly.

Frequently Asked Questions (FAQs)

1. Is SFC safe to use?

Yes, the SFC command is completely safe. It only scans and restores system files without deleting or altering personal data.

2. How long does SFC /scannow take?

It usually takes between 10 to 20 minutes, depending on your computer’s performance and the number of files scanned.

3. Can I use my PC while SFC is running?

You can, but it’s better to leave the scan undisturbed to avoid interference or slower performance.

4. Does SFC fix all problems in Windows?

Not always. If SFC cannot repair files, run DISM /RestoreHealth, then rerun SFC /scannow for best results.