Use the System File Checker tool to repair missing or corrupted system files
If some Windows functions aren’t working or Windows crashes, use the System File Checker to scan Windows and restore your files.
Though the steps below might look complicated at first glance, just follow them in order, step-by-step, and we’ll try to get you back on track.
Run the System File Checker tool (SFC.exe)
- Open an elevated command prompt. To do this, do the following as your appropriate:
If you are running Windows 10, Windows 8.1 or Windows 8, first run the inbox Deployment Image Servicing and Management (DISM) tool prior to running the System File Checker. (If you are running Windows 7 or Windows Vista, skip to Step 3.)
Type the following command, and then press Enter. It may take several minutes for the command operation to be completed.
Important: When you run this command, DISM uses Windows Update to provide the files that are required to fix corruptions. However, if your Windows Update client is already broken, use a running Windows installation as the repair source, or use a Windows side-by-side folder from a network share or from a removable media, such as the Windows DVD, as the source of the files. To do this, run the following command instead:
Note: Replace the C:\RepairSource\Windows placeholder with the location of your repair source. For more information about using the DISM tool to repair Windows, reference Repair a Windows Image.
At the command prompt, type the following command, and then press ENTER:
The sfc /scannow command will scan all protected system files, and replace corrupted files with a cached copy that is located in a compressed folder at %WinDir%\System32\dllcache.
The %WinDir% placeholder represents the Windows operating system folder. For example, C:\Windows.
Note Do not close this Command Prompt window until the verification is 100% complete. The scan results will be shown after this process is finished.