there are two ways to recover this file.
1. restore your computer- go to command prompt and type rstrui.exe command and hit enter. once you will hit enter then you will get restore window. so you can simply restore your computer to the back date. when it was working fine.
2. run the recovery disk or windows installation disk to repair operating system-
if you are not able to restore your computer then you need to insert the windows recovery disk or windows installation disk on your computer and repair your operating system.
it will recover your file.