it might have an .INF extension. Look at page 4 of this PDF

http://www.g1sat.com/files/NERA_Fleet_MPDS_USB.pdf

But regardless, based on what"m reading it sounds like you can run the terminal software using the Windows Standard Modem set for 115.2k BPS. Assuming the USB device is detected by Windows, you need to identify the USB device as a Standard Modem, edit the properties to set the port speed (check the com port number assignment), and then start your terminal software (using compatibility mode as discussed above) then within your software make sure it is set up to use the same com port as your USB modem is defined at.

If you need to change the com port number assignment (perhaps your terminal program only works with Com 1-4 and windows defaulted to Com 10 or something) just edit the Port properties under "Ports" in Device Manager and choose the Port Settings tab, then click Advanced and you will see the number assignment settings. If you choose a lower number Windows may warn you the port is in use, but really that means the port number assignment is in use (for another device that might not be plugged in). Do not choose Com 1 (maybe 2 either) for a USB device because that will conflict with hardware actually installed (your physical serial ports).

One more thing -- you should make sure your modem settings agree with the port settings (for that same com port assignment) in Windows Device Manager.

If you need any more than this I'm going to start billing $