I am using Realtek HDA version sound driver from Asus ROG community which will update frequently. Sometimes the realtek tray icon won't show in tray after a reboot. If it happens to you, then add following key to your registry .. type "regedit" in run command, go to this place Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run and then on right side right-click and select new string value and name it "realtekgui" or any name you want. then edit that value as "C:\Program Files\Realtek\Audio\HDA\RtkNGUI64.exe" -s (assuming that you are using windows 10 x64 and using default install folder for realtek) make sure that above file exist in the path after you installed driver. the -s parameter is to start it in silent mode. after that close registry, just logoff and logon to see the realtek tray icon.
@chillgates : Regarding the tray icon, If you want to keep it whether you do a clean install or an update of HDA drivers, you must stay on the HDA drivers (HDA - FF00) after a clean install of Windows 10 and do not switch to UAD drivers without uninstall UAD drivers. You don't need to make manual trick/changes to the registry if you do things properly.
I did some mess up lately by trying windows dolby access and third party dolby driver for realtek etc. Third party driver didn't install properly when i tried to install in safeboot mode. Then i reverted back to HDA driver. I think i tested UAD also once. Finally the full uninstall of realtek driver through DDU software ( as suggested by other guy in other thread ) and re-installing HDA again gave back tray icon correctly. My windows is a fresh install (20 days only). I shouldn't have mess with dolby drivers. BTW my philips 5.1 speakers got built-in "prologic" option. I think that is alternate name to dolby. It turns every sound to 5.1 so no need of messing with drivers.
switching from HDA or UAD (or vice versa like UAD to HDA) should always require a complete uninstall of the existing one and then a clean install of the new one by the way, what Win10 version were you running, chillgates?
I'm beginning to think that the 1903/1909 versions of Win10 don't like the HDA FF00 drivers (unless you have figured out how to disable automatic driver updates completely) and insist on installing UAD drivers on your Gigabyte board (and possibly overwriting the HDA driver with a UAD version). seems like only the Win7, 8.1 and Win10 LTSB 2016 v1607 (and maybe LTSC 2019 v1809) OS versions could safely use HDA FFxx drivers on your Gigabyte board. using DDU alone may not be enough. you should also use RAPR (driverstore explorer) to remove other SoftwareComponent and Extension drivers related to Realtek, Dolby, etc.