The annoying "beep" error sound in Windows can be quite annoying, and I'm not the only one who thinks so. There are two excellent open source tools that can help with this problem: EarTrumpet i Volume2 and both can be easily installed using the Scoop command scoop install eartrumpet volume2.

If you're specifically looking to reduce the volume of that one annoying "bing" Windows error notification, I've opted to implement a solution from the post on how to reduce the volume of annoying Windows notifications as this is my preference.

You need to open a PowerShell window as an Administrator and copy and paste the following

$n="Windows Notify System Generic"; $p = "${Env:WINDIR}\Media"; cp "$p\$n.wav" "$p\$n.wav.bak"; taskkill /f /im explorer.exe; explorer.exe; curl.exe -o "${p}\${n}.wav" "https://blog.zhaytam.com/audio/Windows-Notify-System-Generic.wav"

Don't worry, there needs to be a "glitch" as the Explorer process needs to be restarted as it probably holds a lock on the desired audio file.