But here's a 3rd party solution that should do the trick:
Setvol.exe 100 (or any number between 0-100)
Make a shortcut for your optimal number and place it in the startup folder.
If you got a keyboard/numpad input, you can map hotkeys to the shortcut: setvol +10 (or -10) for your very own custom vol adjustment keys. If not, you can use girder to map whatever input u got for this use.
Google almost always holds the answer.