CHKDSK
Computer program
In computing, CHKDSK is a system tool and command in DOS, Digital Research FlexOS, IBM/Toshiba 4690 OS, IBM OS/2, Microsoft Windows and related operating systems. It verifies the file system integrity of a volume and attempts to fix logical file... Wikipedia
Initial release: 1980; 44 years ago
Written in: MS-DOS: x86 assembly language; FreeDOS, ReactOS: C