There are two ways to check your Windows files for consistency and attempt to repair them:
Microsoft's System File Checker (offline)
Run
sfc /scannow
in a command prompt as administrator.Microsoft's System Update Readiness Tool (online)
Download and run it.
They will compute hashes of your files. If they mismatch they will attempt to restore the correct file from respectively an offline or online copy. This should help you get the correct file back.