How can I keep a work window visible when a full-screen app takes over the display?

First, work out which mode you’re seeing. A full-screen app fills the display; a maximized window is enlarged but may still leave system controls visible; an ordinary window occupies only part of the display. On a Mac, Apple distinguishes full screen from maximizing: in full screen, the app fills the display, while maximizing leaves the menu bar and Dock visible. [S1]

If you can see the app’s controls, look for its own option to leave full screen or return to a window. On a Mac, hover over the green window button and choose “Exit Full Screen,” or click the Zoom button, as Apple documents. [S1] If the app is merely maximized, restore or resize it using its window controls instead. Avoid installing utilities just to force a window on top.

It can help with ordinary window states, but it is not a universal full-screen exit. Microsoft documents Windows key+Up Arrow and Windows key+Down Arrow for moving the focused window among minimized, windowed, and maximized states. [S2] The shortcut acts on the focused window, so it may affect the app covering your work rather than reveal the window behind it—and Microsoft’s guidance does not establish that it exits every app’s full-screen mode.

Try it only when you know which app has focus and the result you want. If the app stays full-screen, use its own visible controls or menu to look for an exit-full-screen or windowed-mode option. If you cannot find one, consult that app’s help rather than using a tool that overrides system behavior.

Prefer switching apps over closing anything. On a Mac, Apple describes moving between full-screen apps and using Mission Control to see and switch among spaces and windows. [S1] The source supports those Mac options, but it does not establish that every app or macOS version presents them identically. For other systems, use the operating system’s normal app-switching controls, or the app’s own window menu if available.

A safe sequence is: note the full-screen app’s name; try the standard app switcher or overview; select the work app; and confirm that the work window is visible before changing or closing anything. If the work app is still hidden, return to the full-screen app and exit its full-screen mode using supported controls. Don’t dismiss a system or security prompt just to get to a window.

Use this short decision plan:

1. Look: Does the app fill the display, or are system controls and other windows still visible? Treat this as a clue, not a guarantee; apps and interfaces differ.
2. Switch: Try the normal app switcher or overview and select the work app. Avoid closing the covering app as a first move.
3. Restore: If it is a regular maximized window, use its restore control. On Windows, the documented Windows key+Up/Down Arrow shortcuts change the focused window’s minimized, windowed, and maximized states. [S2]
4. Exit full screen: On a Mac, use the green-button menu’s “Exit Full Screen” or the Zoom button. [S1] Otherwise, look for the app’s own full-screen control or help.
5. Check: Confirm the work window is visible and usable before continuing. If a security prompt is involved, stop and follow its intended instructions; don’t try to override it.

Example note to keep beside your device: “App covering work: [app name]. System: [Mac/Windows/other]. Mode appears to be: [full-screen/maximized/unsure]. Tried: [normal app switcher/app’s exit control]. Result: [what changed].” That record helps you resume troubleshooting without guessing or closing unsaved work.

The cited guidance covers specific Mac and Windows actions; it does not establish a universal shortcut, guarantee how an individual app behaves, or explain how to bypass prompts. When the steps don’t match what you see, consult the operating system or app’s own help.