System File Checker is inbuilt tool preinstalled in all modern Windows system. This command utility can repair corrupt system file of windows operating system. To use this utility you have to access DOS. if booting problem in windows 10 then boot with os dvd and go to repair mode and open command prompt then run the command.
Step-1 Open DOS as administrative privilege
Step-2 Run Sfc /scannow command.
Step-3 wait few seconds or a minute.
That’ll System File Checker complete its task. If any problem exist then it will automatically fix issues.
Reboot once and continue to use 10.