Presenting to multiple screens
PsychoPy Builder components can only present to a single screen. However, locally you can create a window on another screen and present to it using code components.
Select which screen is used by your main components in Experiment Settings / Screen
Define your second window and create visual objects in Begin Experiment
win2 = visual.Window(size=[640, 480],color = [0,0,0], fullscr=False, screen=2)
message = visual.TextStim(win2, text= '')
Use object.draw() and win2.flip() commands whenever you want to update the objects.
message.text = "Press space to start"
message.draw()
win2.flip()
Close the window in End Experiment
win2.close()
Note that there may be some inconsistencies in screen numbering. When I set both win and win2 to screen 2, they appear on different screens. I think this is because the code component starts numbering from 0, and Experiment Settings start from 1.
Also, while in principle it should be possible to make the second window full screen using fullscr=True, when I just tested it, they both appeared on the same monitor (i.e. with only one of the two windows visible). It might be worth trying to create both windows in code.