If Windows 11 is crashing, freezing, or behaving unpredictably, corrupted system files may be the cause. Microsoft includes a built-in tool called System File Checker (SFC) that scans and repairs protected Windows system files automatically.

This guide explains how SFC works, how to run it properly, and what to do if it cannot fix the problem.

What Is SFC?

System File Checker (SFC) is a command-line utility that scans Windows system files and replaces corrupted or missing versions with clean copies stored in the Windows component store.

It can help resolve issues such as:

• Random crashes
• Blue screen errors
• Missing or damaged DLL files
• Windows Update failures
• Built-in apps not working properly
• System instability after malware removal

SFC does not remove viruses. It only restores official Microsoft system files.

How to Run SFC in Windows 11

Step 1: Open Command Prompt as Administrator

1. Press the Start button.
2. Type cmd.
3. Right-click Command Prompt.
4. Select Run as administrator.

You must run SFC with elevated privileges or it will fail.

Step 2: Run the Scan

Type the following command:

sfc /scannow

Press Enter.

The scan will begin immediately. It typically takes between 5 and 20 minutes depending on system performance.

Do not close the window while the scan is running.

Understanding the Results

After completion, you will see one of the following messages:

1. No Integrity Violations

“Windows Resource Protection did not find any integrity violations.”

No corrupted system files were detected.

2. Corrupt Files Repaired

“Windows Resource Protection found corrupt files and successfully repaired them.”

Issues were detected and fixed. Restart your computer.

3. Corrupt Files Found but Not Repaired

“Windows Resource Protection found corrupt files but was unable to fix some of them.”

This usually means the Windows image itself is damaged. You must use DISM before running SFC again.

How to Fix SFC Errors Using DISM

If SFC cannot repair files, run this command first:

DISM /Online /Cleanup-Image /RestoreHealth

Wait for the process to complete. It may take several minutes.

Once finished, run:

sfc /scannow

again.

DISM repairs the Windows component store, which SFC relies on.

When Should You Use SFC?

SFC is recommended if you experience:

• System crashes without clear cause
• Broken Windows features
• Update errors
• Post-malware cleanup instability
• File integrity warnings

It is a safe, built-in diagnostic tool and does not modify personal files.

Viewing Detailed Repair Logs

To extract SFC repair information into a readable file, run:

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

This will create a file named sfclog.txt in your current directory.

SFC vs DISM: What Is the Difference?

• SFC scans and repairs system files.
• DISM repairs the Windows image itself.

If SFC fails, DISM is typically required before retrying.

System File Checker is one of the most useful built-in Windows repair tools. It is simple to run, safe to use, and often resolves system corruption without requiring a full reinstall.

For persistent issues, pairing SFC with DISM provides a more complete repair approach.

Read the full article: https://luckyy.uk/how-to-run-sfc-scannow-in-windows-11-to-repair-corrupted-system-files/