GTP4. Cannot get sound.

Hello

I am a complete newb at the DAW thing and am getting off to a very discouraging start.
Story so far; I have a new PC running W7 64bit. I have used Boss BR recorders in the past but have decided to go down the DAW route. I am a guitarist but I want to try some MIDI also. Decided to go with Cakewalk, start off simple with Guitar Tracks Pro 4 USB (Duo Capture). Installed everything on the disk including Guitar rig LE. Installed updates for both GTP and GR. GTP is running version 4.0.5.6 and GR is running 3.2.1.004x64.
Firstly I tried to get some sounds out of Guitar Rig using the Duo Capture. All the metering bars on the screen show signal is going in but nothing is coming out of the stereo i have hooked up to the Sound Card. Tried all sorts of audio configurations and still nothing. So moved on to Guitar Tracks Pro itself. I tried running my Boss GT-10 into the sound card using the SPDIF socket and get the same story.

I am sure that, as a complete novice, I have missed some simple steps, but the instructions don't help. Can someone give some advice.

System: 
i7 2700K on Gigabyte X68 MB. 
16 GB DDR 3 1600 MHz RAM. 
System HDD 1TB, Data HDD 3TB (both 7200 rpm). 
GT 520 GPU. 
Asus D2X sound card.
Windows 7 64 bit.

Know this is old, but sounds lke just a simple routing problem, Input-Sound card, out put -Soundcard or speakers on PC, whatever you want to listen through. Make sure you have Sound Cards checked in Audio inputs, or that they even there? Should be very simple, just check those things, and there are millions of videos on connecting interfaces, especially Cake products. Good Luck anyways, get back to GTP4, so much more available to you!!!!