Second Screen Gaming Coming soon on Steam

Game minimizes when you click your second monitor?

It is not your PC. It is how fullscreen works on Windows, and it can be fixed.

Why it happens

In exclusive fullscreen, a game takes over the display and runs it at its own resolution and refresh rate. Only one program can own a display that way, so the moment you click a window on another monitor, Windows hands the display back to the desktop and the game minimizes to get out of the way.

Games built on SDL, a library many games use for their window, minimize on focus loss unless they are told not to, which step 4 below does.

Free fixes first

  1. Switch the game to borderless windowed in its video settings. It may be called "Fullscreen windowed", "Windowed fullscreen" or "Borderless".
  2. No borderless option? Try Alt+Enter, which switches many games between fullscreen and windowed.
  3. Run it windowed at your screen's resolution, then drag it into place.
  4. For games built on SDL, add a user environment variable named SDL_VIDEO_MINIMIZE_ON_FOCUS_LOSS with the value 0, then restart Steam so the games it launches pick it up.

When the free fixes are not enough

Plenty of games have no borderless mode. Windowed mode keeps a title bar and a frame around the picture, a window you dragged into place opens on the main screen again next launch, and some games forget their window mode after an update.

How Second Screen Gaming fixes it

Run borderless on a chosen screen strips the game's window frame and fits the window to the monitor you pick, the same way Windows places a maximized window. The game keeps rendering at the resolution it has set, and the picture fills the screen.

The tray agent keeps the fit in place. If the game recreates its window or puts its frame back, it is fitted again, and the next time the game starts it lands on the same screen.

Nothing is injected into the game, which is why this is the one runtime fix that stays available for games with anti-cheat.

A game in exclusive fullscreen cannot be reshaped from outside, so set it to windowed mode in its own settings first. Games from the Xbox app run inside a host window that does not take the change.