The projector is on, forty people are watching, and your laptop is about to show them something. The difference between a professional five minutes and a memorable-for-the-wrong-reasons one is a two-minute checklist you run before you plug in.
Two minutes before you present
- Save everything, then close every appexcept the presentation. An app that isn’t running can’t interrupt you, appear in a screen-share picker, or stall the machine while your slides load. One click with a tray kill switch (below), or manually — Mac loop / Windows loop.
- Kill notifications at the OS level:macOS — Do Not Disturb from Control Center (macOS auto-enables it while mirroring, but set it manually anyway; auto-detection misses some setups). Windows — Focus Assist → Alarms only, and check “when duplicating my display” is on.
- Desktop hygiene: wallpaper neutral, no client-named files visible — the desktop flashes on screen every time you switch apps.
- Power: plugged in, sleep timer off (both OSes happily sleep mid-Q&A).
- Open only the deck, presenter view on your screen, and do one display-switch test before the audience files in.
Why “close everything” is step one
Every other failure mode flows from running apps: the calendar alert with the candidate’s name, the chat preview, the browser session from last night, the fan spin-up because something updated itself mid-demo. Notifications settings catch banners; they don’t catch badges, bouncing icons, or the share-picker showing every open window. Closed apps generate none of the above.
The one-click version
Captain Kill Switch turns step 1 into a single click on the menu bar / system tray: every app gets a clean close request, everything’s gone within about two seconds, and the system itself is protected by an allowlist. It exists for exactly this moment — the strategy is save → click → present. Free on macOS, Windows, and Linux.
Order matters:the click doesn’t wait for save dialogs — unsaved work closes. Saving is why the checklist starts with it.