diff --git a/src/Main/options.cxx b/src/Main/options.cxx
index 7bcf2c6..f2d0a2d 100644
--- a/src/Main/options.cxx
+++ b/src/Main/options.cxx
@@ -130,7 +130,7 @@ void fgSetDefaults ()
 
     fgSetBool("/sim/terrasync/global", false);
     fgSetString("/sim/sound/ttsurl", "");
-    fgSetBool("/sim/startup/fullscreen", true);
+    fgSetBool("/sim/startup/fullscreen", false);
     fgSetBool("/sim/menubar/visibility",false);
     
     fgSetBool("/sim/rendering/photoscenery/enabled",true);  //打开卫星地景