What is chk?

CHK is a prefix used in file extensions for files that contain a copy of the data recovered by the CheckDisk utility in Windows operating systems. CheckDisk is a diagnostic tool that detects and fixes errors or bad sectors in hard drives. When CheckDisk runs, it creates a report of any data it recovers and saves it as a CHK file, typically with the extension .chk. CHK files are generally temporary files created by the CheckDisk utility and are not meant to be used directly by users. They can be safely deleted once the original files have been restored. CHK files can be opened and recovered using specialized recovery software.