"HD Audio controller" rings a bell. I see that phrase related to the audio output system on a VIDEO card.
You see, many video cards output on an HDMI cable, and that system can include audio in the cable lines. But the card normally does not have any access to the mobo's audio chip, and hence the VIDEO card also includes its own audio chip so it can send out sound via HDMI. Yours says its chip can output 7.1 audio on the HDMI lines. In most cases like this, when you install the vid card and then its drivers are installed, the setup utility then makes the audio system in the video card the default audio output device in Windows.
That means that your system has two audio output hardware devices - the one on the mobo, and the one on the video card. Now Windows itself can only use ONE audio output device at a time, and there's a place in Windows where you get to specify that. My guess is right now it is set to use the system in the video card.
First, though, you need to decide how you want to proceed. IF you want all audio output to be handled by the mobo system, you can change the way Windows is set. Click on the icon at bottom left and use menus to select Windows System ... Control Panel ... Sound. There you'll see a list of hardware audio devices in your system, and can choose which one will be used a Windows' Default Playback Device. (There are similar choices to be made for the Default Recording Device and the Default Midi playback device.) If you choose the mobo system for playback, then audio will be coming from the jacks on the rear connector port panel and from your front jacks. If you have a separate speaker system, OR if you are using speakers in your monitor, you will need to connect the feed cables for those speakers to the jacks on the back panel.
On the other hand, IF you want audio to come through the HDMI output of the video card and go to whatever device system is at the other end of that HDMI cable, then set the video card's audio system to be Windows' Default Playback device. But then there will be no audio signals coning out of your case's jacks. If you want audio on your headphones, you'll have to find how to get that from the external speakers or whatever you're using.
The third option is to be able to use both output systems, but not at the same time. You can connect stuff up to whichever output jacks or HDMI cable you like. Then you can use that Windows Default Playbeck Device panel to make a change whenever you want to go to using headphones (from the front jack) or to speakers in the Monitor, or whatever.