MS-DOS / PC DOS and some related disk operating systems use the files mentioned here.
System Files:[1]
Command-line interpreter (Shell):
This is the command interpreter.
User configuration files:
This is run by the default shell (usually COMMAND.COM) to execute commands at startup.
This contains statements to configure DOS and load device drivers.
Standard DOS utility programs:
Set a search path for data files.
Redirect requests for disk operations on one drive to a different drive.
Set or display file attributes.
Check disk for file system integrity.
File compare utility.
Simple command line debugger.
Delete a directory tree.
Compare floppy disks.
Copy floppy disks.
Command line editor.
File compare utility.
Partitions fixed disks.
Find text in files.
Formats disks.
Joins a drive letter to a subdirectory.
Set or remove a disk volume label.
Display memory usage.
Set modes for system devices.
Display output one screen at a time.
Move files from one directory to another.
Print spooler.
Replace files.
File sharing and locking support.
Sorts input.
Substitutes a drive letter for a subdirectory.
Transfers the system files to another drive to make it bootable.
Display a directory tree.
Extended file copy.
Standard DOS device drivers:
ANSI console driver.
Expanded memory manager.
Extended memory manager.