It happens Many Time that we tweak with our Windows file but after tweaking we see that Windows is not working as it should due to that file.And some System restore also not work for this problem.Then you left with only option and that is is a Clean Re-Installation of Windows.
But now you can fix your all Windows File by just Using Command Prompt.Windows has a ?System File Checker option which will check all files under windows and then if it finds any curropted file it will replace it with default one.
So in order to use System File Checker, Run Command Prompt as Administrator.
And then give following command in it.
Then it will scan your whole system and takes some time.
If it finds any curropted file then it will replace it with the original one on the next boot