MS-DOS / PC DOS and some related disk operating systems use the files mentioned here. System Files: IO.SYS (or IBMBIO.COM): This contains the system initialization code and builtin device drivers. MSDOS.SYS (or IBMDOS.COM): This contains the DOS kernel. Command-line interpreter (Shell): COMMAND.COM: This is the command interpreter. User configuration files: AUTOEXEC.BAT: This is run by the default shell (usually COMMAND.COM) to execute commands at startup. CONFIG.SYS: This contains statements to configure DOS and load device drivers. Standard DOS utility programs: APPEND: Set a search path for data files. ASSIGN: Redirect requests for disk operations on one drive to a different drive. ATTRIB: Set or display file attributes. BACKUP / RESTORE: simple backup and restore utilities. CHKDSK: Check disk for file system integrity. COMP: File compare utility. DEBUG: Simple command line debugger. DELTREE: Delete a directory tree. DISKCOMP: Compare floppy disks. DISKCOPY: Copy floppy disks. DOSKEY: Command line editor. EDIT / EDLIN: Very basic text editor(s); EDLIN is in earlier versions. FC: File compare utility. FDISK: Partitions fixed disks. FIND: Find text in files. FORMAT: Formats disks. JOIN: Joins a drive letter to a subdirectory. LABEL: Set or remove a disk volume label. MEM: Display memory usage. MODE: Set modes for system devices. MORE: Display output one screen at a time. MOVE: Move files from one directory to another. PRINT: Print spooler. REPLACE: Replace files. SHARE: File sharing and locking support. SORT: Sorts input. SUBST: Substitutes a drive letter for a subdirectory. SYS: Transfers the system files to another drive to make it bootable. TREE: Display a directory tree. XCOPY: Extended file copy. Standard DOS device drivers: ANSI.SYS: ANSI console driver. EMM386.EXE: Expanded memory manager. HIMEM.SYS: Extended memory manager. RAMDRIVE.SYS / VDISK.SYS: RAM disk; VDISK.SYS is in older versions of PC DOS. References DOS files