Master volume

When I change the volume in the toolbar
all sounds on the PC do including audioplayer and
software synthesizer.
Turning down the mixer volume does not
affect the PC sounds but is only for each track.
Is there a master volume that affects audacity only?

Changing the playback volume in Audacity’s Mixer Toolbar affects the master device slider for the playback device selected in Device Toolbar.

Not supplied by Audacity. But if you play a sound in Audacity then click the speaker icon by the system clock, then click “Mixer”, there is a playback slider for Audacity. You can turn that slider down without turning affecting the master device slider. If you turn up that Audacity slider above the level of the master device slider, the master device slider will also turn up.