Windowed to Fullscreen Mode

Changing from Windowed Mode to Fullscreen Mode sometimes causes other applications to appear in front of the game. If you click on these other applications the game freezes up and can’t be accessed anymore, and reverts back to Windowed Mode. You can still hear sounds coming from the game, and a still picture of the game still lingers on your screen. The only way I found to close the game is using Task Manager.