How to repair missing or corrupt system files: When using you computer, does Windows give you errors, or is it just not functioning the way it should? have you had Malware on the system and after removing the infected files you are now getting system file errors .sys files .dll files maybe your getting errors saying your files are missing or corrupt or getting BSOD Blue Screen of Death, all these types of files are critical to Windows and need to be running correctly, but all is not lost, let’s try and run sfc /scannow to try and fix or repair these operating system files.
1. Windows 7 : Go to Start Button and type cmd in Search Box now Right Click cmd and Run as Administrator press Enter.
2. Windows 8: Go to Charms Bar and Click on Search, now type cmd
Now on the left of the screen right click Command Prompt then at bottom click Run as Administrator
Now type sfc /scannow
It will now run a scan on all your system files to see if they are missing or corrupted, if it finds errors with system files it will attempt to fix or replace them.
Scan is now complete, you should see details of what the scan found on the screen.