Recovered File Fragments
CHK files are usually created in Microsoft Windows or old MS-DOS Operating Systems when ScanDisk or CHKDSK disk checking tools find and fix lost cluster errors in your Hard Disk, such files will contain the contents of the located clusters (File Fragments).
Lost clusters problem can be caused by system crash's or unproper system shutdowns (for example due to power failure) while writing information to files on the Hard Disk, this may cause discrepancies in the file system information for such files, thus originating that some of the information being written to the hard disk at the time of the crash/shutdown to get "lost" over the hard disk and not associated with the proper file(s).
Usually CHK files are created with file names like FILEXXXX.CHK and stored in a folder named FOUND.000 at root of the Hard Disk.
Often these files can be just manually deleted to save disk space, unless you know they contain critical information you have been working on when system crash/shutdown happened and you want to try to recover it.
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