System files are always in protected mode to prevent programs from editing them and in turn messing up with the Windows installation. But sometimes, we might need some apps to have control over system files. System Files Lister is a small freeware utility that checks files protected by System File Checker mechanism used with the Windows File Protection (WFP) feature in Windows. This feature does allow to protect core system files from being accidently or intentionally modified by third party programs.
If System File Checker discovers that a protected file has been overwritten, it retrieves the correct version of the file from the cache folder (%Systemroot%\System32\Dllcache) or the Windows installation source files, and then replaces the incorrect file.
When you run the tool, it lists out all the files protected by this mechanism, you can select any file and then check for the protection status.
The application is portable and can be used from a USB drive as well.