I'm assuming you're using a PC. Harder but doable. First install the drivers for the GPS. If you don't have them download them from the internet. Find the co that made the GPS.

Once installed you can plug the GPS into the port you will ALWAYS use for it. PC's don't like change. :) Then after you do that you can most likely go to the device manager to select the port you put it in. It will most likely be the only port listed for the device.

Fair Winds