This step-by-step article describes how to map COM ports for compatibility with MS-DOS-based programs by using the change port command in Windows 2000 Terminal Services.
You can use the change port command to display or change COM port mappings for compatibility with MS-DOS-based programs. Most MS-DOS-based programs support only serial ports COM1 through COM4. You can use the change port command to map a serial port to a different port number so that MS-DOS-based programs can access that serial port.
Note that COM port mappings apply only to the current session. If you log off and then log back on, you must use the change port command to map the COM port again.