Realtek Audio NOT Working? [WINDOWS 10]

So this has been an issue for a while now,
Every time I try and install 'Realtek HD Audio Drivers', My PC doesn't install them, and says it's the drivers aren't compatible. In the sound tab in the taskbar, the 'speakers' don't show up anywhere because Realtek isn't installed. Whenever I go to device manager, under Sound, video, game controllers, It says 'NVIDIA High Definition Audio'. This is a PROBLEM as when I am making music, the volume is pretty LOW and slightly distorted, even when everything is at 100%. My laptop which also runs Windows 10, and Realtek is installed and working on that. When I used Windows 7 before I upgraded to Windows 10 64 bit for my PC, Realtek was installed and also worked fine on that. [could it be a sound card issue?]

I am currently running a HDMI cable from the screen into my graphics card, and the AUX cord from the Sub [and speakers] into the back of my screen. The sound works at the moment but the problem is that the volume is very LOW. I have tried enabling Loudness Equalization in the enhancement tab in the sound options [in the taskbar] and nothing made a difference, I have also tried running the AUX cable into the motherboard and sound card from the Sub, but no sound comes through.

Here are also pictures that show what the problems are.

Is this an OEM PC or a custom build? If an OEM....need the brand/make/model of it. If a custom built PC....need the complete system specs.

I bought it off a friend 4 years ago, i think it's custom built

Processor: Intel (R) Core (TM) 17-3770 CPU @ 3.40GHz
System Model: To Be Filled By O.E.M
System manufacturer: To Be Filled By O.E.M
Motherboard: ASROCK z77m
Graphics Card: NVIDIA GeForce GTX 760
System type: 64 bit, 65x Processor
RAM: 8gb

Great.....now....what bit is your OS...32 or 64?

You can download your mobo sound driver directly from ASRock.......just pick your OS and bit type.

ASRock > Z77M

Are you sure, you have Realtek audio? For the record, you can find the latest drivers here:

Download Realtek HD Audio Driver 6.0.1.7936 for Windows 10, Windows 10 64 bit

Latest Realtek HD Audio Driver Version - Windows 10 blog

I am using an ASRock Z77 Professional Fatal1ty motherboard (using the same i7 3770 CPU). It has Realtek and is Win 10 compatible, using the Realtek drivers direct from Realtek.

However, if you are using HDMI audio, then that is generated in the NVIDIA Video Card, not from Realtek.

I have a recording studio (Sonar). I wonder if the Akai synthstation is causing any conflicts. Temporarily disable that and see what happens.