dedicated serial connection

What’s the meaning of: dedicated external serial, male 9 pin connector? I’ve just bought a device with a RS-232 controller. Windows xp doesn’t detect it. I’ve installed the driver,( the device is a touch screen), however I am unable to finish the calibration. One of the system requirements is for the serial connector to be “dedicated”. The modem is on com8. The device is connected to com1, no conflicts.