1.Click Search (the lenses icon) in your task bar, type CMD, Right Click on Command Prompt and select Run as Administrator
2.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. At the command prompt, type the following command, and then press ENTER:
DISM.exe /Online /Cleanup-image /Restorehealth
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 Note Do not close this Command Prompt window until the verification is 100% complete.