Some windows need killing when a puzzle is complete. Close all extra windows.

EduNetworkBuilder/Network.cs

@@ -817,14 +817,30 @@ namespace EduNetworkBuilder
                     Properties.Settings.Default.Save();
                 }
             }
+            //kill all extra windows that no longer need to be open.
+            KillAllExtraWindows();
+
             DialogResult answer = MessageBox.Show(NB.Translate("N_MarkAsSolvedDone"),NB.Translate("_Solved"),MessageBoxButtons.YesNo);
-            if(answer == DialogResult.Yes)
+
+            if (answer == DialogResult.Yes)
             {
                 ListBoxWindow LBW = new ListBoxWindow();
                 LBW.ShowDialog();
             }
         }
 
+        void KillAllExtraWindows()
+        {
+            for(int i = Application.OpenForms.Count -1; i >=0; i--)
+            {
+                if (Application.OpenForms[i].Name == "BuilderWindow") continue;  //We do not kill the builder window
+                if (Application.OpenForms[i].Name == "RTFWindow") continue;  //We do not kill the rtf window
+                Application.OpenForms[i].Hide();  //make them disappear
+                Application.OpenForms[i].Close(); //actually close them
+            }
+        }
+
+
         /// <summary>
         /// See if we have any tests that are supposed to check for packet arrival.
         /// </summary>