Windows operating system comes with built-in tools popularly known as SFC & DISM that can be used to check the System Files on your computer for errors and repair them.
The SFC (System File Checker) tool is designed to check the integrity of system files on your computer and automatically replace them with correct version files, in case they are found to be missing, corrupted, damaged or changed.
If the SFC Scan is unable to run or reports errors, you can use the DISM (Deployment Image Servicing and Management) tool to check and fix the possibility of the SFC tool being damaged or corrupted.
In certain cases, System File Checker (SFC) may ask you to run the DISM tool to fix certain files that could not be repaired by the SFC tool.
1. Steps to Repair Corrupted System Files Using SFC
Follow the steps below to run SFC command to repair corrupted or damaged Windows System Files.
1. Type CMD in the Search bar > right-click on Command Prompt App in the search results and select Run as Administrator option.
2. When prompted, enter your Admin Password to open Command Prompt As Admin.
3. On the Command Prompt window, type sfc /scannow and press the Enter Key on the keyboard of your computer.
Note: There should be a space after sfc.
4. Patiently wait for Windows to scan the computer for System File Errors and fix them.
It may take anywhere from 10 to 20 minutes for the full system scan to be completed. Once the SFC scan is completed it will come up with one of the following results.
- Windows Resource Protection did not find any integrity violations (which is a good result)
- Windows Resource Protection found corrupt files and repaired them (better than good!)
- Windows Resource Protection found corrupt files but was unable to fix some (or all) of them (not a good result)
In case you get the third message, you need to take the help of DISM tool to fix the problem.
2. Steps to Repair System Files Using DISM
1. Type CMD in the Search bar > right-click on Command Prompt App in the search results and select Run as Administrator option.
2. On the command prompt window, type DISM /Online /Cleanup-Image /RestoreHealth and press the Enter Key.
Note: There needs to be a space after DISM, Online and Cleanup-Image.
3. Wait for the DISM tool to check your computer for errors and fix them.
The DISM process may take anywhere from 10 to 15 minutes or more. Also, the progress bar may not show up for a while and you may find the progress stuck at 20 percent for a long time.
After the DISM command has finished running, restart your computer and run the SFC command once again to replace remaining corrupted files (if any) with the correct ones.