“Is another program using the port? Quit Pocket-NAV to use this program” simply means that the 302 and your computer have failed to connect.

I assume that you are using a computer with a USB port, and a serial to USB converter. My experience was that it took me several tries to find a USB converter that would work with the 302. I strongly recommend the USB mod to the 302, and a remote USB port mounted on the instrument panel for easy down loads.

On my Win XP machines, I use Com 2. On my Win 7 machine, I use "other" with "3" in the box. Why that works rather than just checking the com 3 box is well above my pay grade.

Once you get connected, you will need to deal with "Crazy Mouse Syndrome". Windows often recognizes a GPS device as a mouse, sending your curser careening across the screen, rendering your computer unusable. That is an easy fix, Google is your friend here.

Your next challenge, if you are using Win 7, is that a driver is needed. Be sure that you are connected to the internet so Windows can hunt it down for you and load it.

Or wimp out and hit e-Bay for a legacy computer with a serial port.

The only glitch I have ever had is that after trailering down rough dirt roads sometimes the plug for the temperature sensor will wiggle partly loose. When that happens, the system will freeze during boot up. Just turn it off, pull it out, and push it back in.

P9