I am assuming here that you have the audio input cable plugged into the MOBO's rear panel output bank; if it's in a front panel jack, post back - that's a different set of problems - front panel plug type, detection, and BIOS settings...
First question is: does the LED on the Bose's control module show yellow, and then turn green when you touch the top? If not, review page 9 of the manual, and double check your connections...
Next, click on the system tray (right hand corner of your taskbar) to show this:
Double click on the speaker icon to open this:
Now, on the left side "Speaker Configuration" drop-down, you will want "Stereo" selected;
your MOBO uses the green jack, by default, as the 2-channel output:
"Line Out Jack (Green)
The default line out jack. Use this audio jack for a headphone or 2-channel speaker"
If you're not plugged in there, that's your problem; don't worry, you don't need to crawl around to re-do it - you can simply set up what you've got (assuming you aren't plugged into blue or pink - those are verboten)...
Note that, in the above picture, three of my "Analog Back Panel" jacks look 'solid', and three are kind of 'dimmed out'? When you plug in a jack, it will look solid - unconnected ones are dim; in your case, you should only have one (and you
should have at
least one) showing 'solid'; right-click on the 'solid' jack, and select "Connector Retasking..." to get the following popup:
select as shown, close it all, and you should have sound...
There have been a few reports of a single jack being either dead or noisy - if still no results, try switching to, and recofiguring for, a different jack...
Good Luck!
Bill