If the slides and notes are on opposite screens in PowerPoint for Windows, choose Display Settings → Swap Presenter View and Slide Show from the screen showing the notes. Check the audience display itself: it should show only the slide.
01Swap the two views during a rehearsal
Section linkPresenter View is the screen with your notes and the next-slide preview. The swap menu is at the top of that screen, even when it is the one facing the audience. Rehearse with a harmless note before showing sensitive material, then advance a slide to verify that only the slide is visible to the audience.
02If both screens show the same thing
Section linkIn Windows, press Windows + P and choose Extend so the screens can show different content. If you need to identify the projector, go to Settings → System → Display → Identify. Back in the desktop PowerPoint app, open Slide Show, check Use Presenter View, and start the show again.
03If you need to choose the screen before presenting
Section linkOn the Slide Show tab, open Set Up Slide Show and look for the monitor options. Automatic normally puts notes on the laptop screen when one is available. Test with the actual projector connected: PowerPoint can switch Windows to Extend during the show and return to Duplicate when the show ends.