There are some hidden dos commands which u can't recognise by typing help in cmd

Here they are with description
COMMANDS:--
ANSI.SYS
Defines functions that change display graphics, control cursor movement, and reassign keys.
APPEND
Causes MS-DOS to look in other directories when editing a file or running a command.
ARP
Displays, adds, and removes arp information from network devices.
ASSIGN
Assign a drive letter to an alternate letter.
ASSOC
View the file associations.
AT
Schedule a time to execute commands or programs.
ATMADM
Lists connections and addresses seen by Windows ATM call manager.
ATTRIB
Display and change file attributes.
BATCH
Recovery console command that executes a series of commands in a file.
BOOTCFG
Recovery console command that allows a user to view, modify, and rebuild the boot.ini
BREAK
Enable / disable CTRL + C feature.
CACLS
View and modify file ACL's.
CALL
Calls a batch file from another batch file.
CD
Changes directories.
CHCP
Supplement the International keyboard and character set information.
CHDIR
Changes directories.
CHKDSK
Check the hard disk drive running FAT for errors.
CHKNTFS
Check the hard disk drive running NTFS for errors.
CHOICE
Specify a listing of multiple options within a batch file.
CLS
Clears the screen.
CMD
Opens the command interpreter.
COLOR
Easily change the foreground and background color of the MS-DOS window.
COMMAND
Opens the command interpreter.
COMP
Compares files.
COMPACT
Compresses and uncompress files.
CONTROL
Open Control Panel icons from the MS-DOS prompt.
CONVERT
Convert FAT to NTFS.
COPY
Copy one or more files to an alternate location.
CTTY
Change the computers input/output devices.
DATE
View or change the systems date.
DEBUG
Debug utility to create assembly programs to modify hardware settings.
DEFRAG
Re-arrange the hard disk drive to help with loading programs.
DEL
Deletes one or more files.
DELETE
Recovery console command that deletes a file.
DELTREE
Deletes one or more files and/or directories.
DIR
List the contents of one or more directory.
DISABLE
Recovery console command that disables Windows system services or drivers.
DISKCOMP
Compare a disk with another disk.
DISKCOPY
Copy the contents of one disk and place them on another disk.
DOSKEY
Command to view and execute commands that have been run in the past.
DOSSHELL
A GUI to help with early MS-DOS users.
DRIVPARM
Enables overwrite of original device drivers.
ECHO
Displays messages and enables and disables echo.
EDIT
View and edit files.
EDLIN
View and edit files.
EMM386
Load extended Memory Manager.
ENABLE
Recovery console command to enable a disable service or driver.
ENDLOCAL
Stops the localization of the environment changes enabled by the setlocal command.
ERASE
Erase files from computer.
EXIT
Exit from the command interpreter.
EXPAND
Expand a Microsoft Windows file back to it's original format.
EXTRACT
Extract files from the Microsoft Windows cabinets.
FASTHELP
Displays a listing of MS-DOS commands and information about them.
FC
Compare files.
FDISK
Utility used to create partitions on the hard disk drive.
FIND
Search for text within a file.
FINDSTR
Searches for a string of text within a file.
FIXBOOT
Writes a new boot sector.
FIXMBR
Writes a new boot record to a disk drive.
FOR
Boolean used in batch files.
FORMAT
Command to erase and prepare a disk drive.
FTP
Command to connect and operate on a FTP server.
FTYPE
Displays or modifies file types used in file extension associations.
GOTO
Moves a batch file to a specific label or location.
GRAFTABL
Show extended characters in graphics mode.
HELP
Display a listing of commands and brief explanation.
IF
Allows for batch files to perform conditional processing.
IFSHLP.SYS
32-bit file manager.
IPCONFIG
Network command to view network adapter settings and assigned values.
KEYB
Change layout of keyboard.
LABEL
Change the label of a disk drive.
LH
Load a device driver in to high memory.
LISTSVC
Recovery console command that displays the services and drivers.
LOADFIX
Load a program above the first 64k.
LOADHIGH
Load a device driver in to high memory.
LOCK
Lock the hard disk drive.
LOGON
Recovery console command to list installations and enable administrator login.
MAP
Displays the device name of a drive.
MD
Command to create a new directory.
MEM
Display memory on system.
MKDIR
Command to create a new directory.
MODE
Modify the port or display settings.
MORE
Display one page at a time.
MOVE
Move one or more files from one directory to another directory.
MSAV
Early Microsoft Virus scanner.
MSD
Diagnostics utility.
MSCDEX
Utility used to load and provide access to the CD-ROM.
NBTSTAT
Displays protocol statistics and current TCP/IP connections using NBT
NET
Update, fix, or view the network or network settings
NETSH
Configure dynamic and static network information from MS-DOS.
NETSTAT
Display the TCP/IP network protocol statistics and information.
NLSFUNC
Load country specific information.
NSLOOKUP
Look up an IP address of a domain or host on a network.
PATH
View and modify the computers path location.
PATHPING
View and locate locations of network latency.
PAUSE
Command used in batch files to stop the processing of a command.
PING
Test / send information to another network computer or network device.
POPD
Changes to the directory or network path stored by the pushd command.
POWER
Conserve power with computer portables.
PRINT
Prints data to a printer port.
PROMPT
View and change the MS-DOS prompt.
PUSHD
Stores a directory or network path in memory so it can be returned to at any time.
QBASIC
Open the QBasic.
RD
Removes an empty directory.
REN
Renames a file or directory.
RENAME
Renames a file or directory.
RMDIR
Removes an empty directory.
ROUTE
View and configure windows network route tables.
RUNAS
Enables a user to execute a program on another computer.
SCANDISK
Run the scandisk utility.
SCANREG
Scan registry and recover registry from errors.
SET
Change one variable or string to another.
SETLOCAL
Enables local environments to be changed without affecting anything else.
SETVER
Change MS-DOS version to trick older MS-DOS programs.
SHARE
Installs support for file sharing and locking capabilities.
SHIFT
Changes the position of replaceable parameters in a batch program.
SHUTDOWN
Shutdown the computer from the MS-DOS prompt.
SMARTDRV
Create a disk cache in conventional memory or extended memory.
SORT
Sorts the input and displays the output to the screen.
START
Start a separate window in Windows from the MS-DOS prompt.
SUBST
Substitute a folder on your computer for another drive letter.
SWITCHES
Remove add functions from MS-DOS.
SYS
Transfer system files to disk drive.
TELNET
Telnet to another computer / device from the prompt.
TIME
View or modify the system time.
TITLE
Change the title of their MS-DOS window.
TRACERT
Visually view a network packets route across a network.
TREE
View a visual tree of the hard disk drive.
TYPE
Display the contents of a file.
UNDELETE
Undelete a file that has been deleted.
UNFORMAT
Unformat a hard disk drive.
UNLOCK
Unlock a disk drive.
VER
Display the version information.
VERIFY
Enables or disables the feature to determine if files have been written properly.
VOL
Displays the volume information about the designated drive.
XCOPY
Copy multiple files, directories, and/or drives from one location to another.