Depends on what you want. I’m on Windows 11, though. But I can set my configuration to 7.1 with 24-bit format.
I do this by selecting the Configure button on my Sound Properties.
Then change the speakers configuration to 7.1
Once you’re done with the configuration, select the same audio device and click Properties.
Then in the default Format select the 24-bit.
For me, doing it that order will get me to have 7.1 channel with 24-bit sound.
You can prevent the change in the configuration or the format by always plugging in the audio device from startup to shutdown. The only time I ever see the format change to 2.0 is if I use Dolby Atmos spatial sound format. While my speakers do support it. Sometimes Windows having trouble keeping the setting, so when the PC powers up and Shuts down, sometimes my speakers are still booting up and Windows may not recognise it’s a valid Dolby Atmos supported speakers so it resets itself to the safest format, 2.0 with 16-bit.