Hi, On NT/2000/XP, you will not be able to use the serial port, once it is assigned to a mouse. On 95/98/Me, you can do this, but you will lose the mouse for the remainder of your Windows session. Mouse output is not very useful for tests anyway.
Get an (old) external modem for your first tests, the ATIx commands return a number of readible strings. Test your actual device with HyperTerminal first, before using LabView. HTH, regards, Matt