System File Checker (SFC) is a Windows tool that checks system files for corruption and helps fix problems that may cause Windows to malfunction. To run it, follow these steps:
Make sure you've installed the latest updates for Windows, and then restart your machine. To find out more, read Update Windows.
In the search box on the taskbar, type command prompt, and right-click or press and hold Command Prompt from the list of results. Select Run as administrator, and then select Yes.
Type DISM.exe /Online /Cleanup-image /Restorehealth (note the space before each "/"), and then press Enter.
Note
This step may take a few minutes to start and complete.
After you see a message that says "The operation completed successfully," type sfc /scannow (note the space between "sfc" and "/") and press Enter.
After you see a message that says, "Verification 100% complete," type exit and press Enter.