System file
A file that is in use by an operating system and cannot be deleted or modified without causing the operating system to no longer work. Often these files cannot be deleted because they're in use by the operating system.
A system file is also an attribute that can be added to any file in Microsoft operating systems that allow the operating system to know the file is an important system file. Files that are marked as a system file will also be hidden files.
- If you're looking for help about a system file and know the name of that file try searching for the name of the file.
Also see: File, Hidden file, Operating system definitions