How to fix and resolve Windows 11 'System File Checker' (SFC) and DISM errors

Summary

This guide helps you troubleshoot and resolve: How to fix and resolve Windows 11 'System File Checker' (SFC) and DISM errors. Follow the steps below to fix the issue.

Common Causes

If your Windows 11 system is experiencing unexpected instability, such as applications freezing or crashing or recurring Blue Screen of Death (BSOD) errors, it may be due to corrupted system files. Windows includes two powerful built-in utilities—Deployment Image Servicing and Management (DISM) and System File Checker (SFC)—designed to analyse and repair these issues without needing to reinstall the operating system.

Quick Fix Steps

For most users, running these tools in a specific sequence will resolve the majority of OS-level corruption. Follow this order for the best results:

1. Run DISM (to repair the system image).
2. Run SFC (to repair the actual system files using the healthy image).
3. Restart your computer.

Detailed Instructions

Step 1: Open an Elevated Command Prompt

Both tools require administrative privileges to modify system files. If you do not run them as an administrator, the process will fail.

1. Click the Start button or press the Windows key.
2. Type cmd into the search bar.
3. In the search results, right-click Command Prompt and select Run as administrator.
4. If the User Account Control (UAC) prompt appears, click Yes.

Step 2: Running the DISM Tool

The DISM tool checks the health of the Windows component store. If the local recovery image is corrupted, SFC will not be able to fix your files; therefore, we run DISM first.

1. In the Command Prompt window, type the following command and press Enter: DISM /Online /Cleanup-Image /RestoreHealth
2. Wait for the process to complete. This may take 5 to 15 minutes depending on your hardware and internet connection.
3. The process may appear to "stick" at 20% or 80%; this is normal behaviour. Do not close the window.

Step 3: Running the System File Checker (SFC)

Now that the system image is healthy, you can run the SFC tool to scan and replace corrupted system files.

1. In the same Command Prompt window, type the following command and press Enter: sfc /scannow
2. The tool will begin scanning all protected system files. This usually takes 10 to 20 minutes.
3. Once complete, Windows will provide a summary of the results.

Understanding the Results

After running sfc /scannow, you will see one of the following messages:

• "Windows Resource Protection did not find any integrity violations." — Your system files are healthy. If you are still experiencing a computer running slow, the issue may be hardware-related or caused by third-party software.
• "Windows Resource Protection found corrupt files and successfully repaired them." — The errors have been fixed. Restart your PC to finalise the changes.
• "Windows Resource Protection found corrupt files but was unable to fix some of them." — This indicates deeper corruption.

Troubleshooting Common Errors

SFC cannot perform the requested operation

If you receive this error, it often means the tool cannot run while Windows is actively using the files. Try booting into Safe Mode:

1. Go to Settings > System > Recovery.
2. Next to Advanced startup, click Restart now.
3. After restarting, navigate to Troubleshoot > Advanced options > Startup Settings > Restart.
4. Press 4 or F4 to start in Safe Mode and repeat the SFC process.

DISM Error 0x800f081f (Source files not found)

This occurs when DISM cannot find the necessary files via Windows Update. You may need to specify a local installation media (USB or ISO) as a source.

Browser issues persist

If you have repaired system files but your browser is still not loading pages, the issue is likely related to your DNS settings, network configuration, or browser cache rather than OS corruption.

Still Having Issues?