Question how to get 7.1 surround on windows 10 again after reinstallation?

[Muqsit_1]

My laptop Asus GL553ve and i purchased it on 2018. the laptop came with pre installed windows 10 and i didn't resintall windows till yesterday. i had all my updates and drivers upto date. i've been playing game like CSGO and Apex legends and music on 7.1 surround on my earphone which is at playback speaker configure. after i reinstall my windows 10 yesterday and when i play Apex legends, the game audio was set on headphone/stereo, so, i went back to control panel -> sound -> playback -> speaker configure to change it back to 7.1 surround and i found olny stereo is available, now i cannot use 7.1 surround sound any more. i tried almost everything updating windows and realteak drivers but still the same. please help, i'm worried that i've lost my sound.

 

[Lutfij]

Latest BIOS update for your laptop? Have you manually installed all drivers for your laptop after downloading them from your manufacturer's support site? Which version on Windows 10 are you on?

 

[Muqsit_1]

Latest BIOS update for your laptop? Have you manually installed all drivers for your laptop after downloading them from your manufacturer's support site? Which version on Windows 10 are you on?

I have the latest BIOS update 308. i gave this laptop to ASUS service center to reinstall windows and when i got the laptop back, all utiliy software installed but i'm not sure how they installed. the current version of Windows 10 is 1809, OS build 17763.864, i turned windows verson back from 1909 because of this problem. now i'm realizing the mistake i've done. i'm depending on you guys