How to Set up the R8600 to Send Data to your Laptop
From The RadioReference Wiki
First, make sure you've loaded the correct USB driver on your computer. You can download the USB driver from Icom here
When you plug your radio in to your computer, it will see it as a sound card and will will treat it as a remote USB sound card. Make sure the USB cable has a USB-B plug for the R8600, the other end should be for your laptop.
So, in the setup menu, when you choose the 'Audio' tab,you'll see boxes for Soundcard input and output. You should have two choices there. One will be PC Speakers (or similar). That will be your PC's internal sound card.
The other available option should be (2-USB Audio Codec). (That will be the sound card inside your radio). Make sure you've chosen 'USB Audio Codec' for both Input and Output otherwise you won't be able to decode any signals. See the picture below. Note that this setup will mute the audio from your PC.