NI-Serial did not recognize every serial interface. There are several reasons why you might encounter this problem:
The serial interface is not properly installed
Refer to the Serial Hardware and Software for Windows Help to verify that your serial interface is correctly installed. Rerun the NI-Serial Troubleshooting Wizard.
You ran the Troubleshooting Wizard before the Add New Hardware Wizard completed the task of adding the Plug-and-Play interface to your system.
Follow the steps in the Add New Hardware Wizard to finish adding the hardware to your system before you run the Troubleshooting Wizard. If you canceled the Add New Hardware Wizard before it completed, reboot your system and make sure the Add New Hardware Wizard completes before continuing with the Troubleshooting Wizard.
You have a non-Plug-and-Play interface, such as a serial ENET interface, and you did not use the Add Serial ENET Hardware Wizard to add the interface to your system properly. The Add Serial ENET Hardware Wizard guides you through the process of adding serial ENET interfaces to your system.
Serial USB interface not detected
The USB host controller must be working properly to use the serial interface. Refer to the Device Manager to verify that the host controller is functioning properly. If you select View devices by type, you can review the USB Host Controller properties to ensure it is correctly enabled and functioning.
PCMCIA serial interface not detected
The PCMCIA adapter must be working properly to use the serial interface. Refer to the Device Manager to verify that the adapter is functioning properly. If you select View devices by type, you can review the PCMCIA adapter properties to ensure it is correctly enabled and functioning.
Serial interface has been removed from the system
You have removed the serial interface from the system. Click on the link below to launch the Device Manager. Right-click on your computer's name in the list and select Scan for hardware changes. You may also reboot your computer to allow the operating system to detect and install your serial interface.