Change port

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Change port

Lists or changes the COM port mappings to be compatible with MS-DOS applications.


change port[{PortX**=**PortY | /dPortX | /query}]

  • PortX = PortY
    Maps COM PortX to PortY.
  • /d PortX
    Deletes the mapping for COM PortX.
  • /query
    Displays the current port mappings.
  • /?
    Displays help at the command prompt.
  • Most MS-DOS applications support only COM1 through COM4 serial ports. The change port command maps a serial port to a different port number, allowing applications that do not support high-numbered COM ports to access the serial port. Remapping works only for the current session and is not retained if you log off from a session and then log on again.

  • Use change port without any parameters to display the available COM ports and their current mappings.


To map COM12 to COM1 for use by an MS-DOS-based application, type:

change port com12=com1

To display the current port mappings, type:

change port /query

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See Also


Command-line reference A-Z
Command shell overview
Terminal Services commands