Disable the windows key only when in gameplay.

osu.Game/Configuration/SessionStatics.cs

@@ -12,12 +12,14 @@ namespace osu.Game.Configuration
         {
             Set(Static.LoginOverlayDisplayed, false);
             Set(Static.MutedAudioNotificationShownOnce, false);
+            Set(Static.DisableWindowsKey, false);
         }
     }
 
     public enum Static
     {
         LoginOverlayDisplayed,
-        MutedAudioNotificationShownOnce
+        MutedAudioNotificationShownOnce,
+        DisableWindowsKey
     }
 }