diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index f14872dd15..20ae07b0c9 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -438,6 +438,7 @@ Application::Application(int& argc, char** argv, QElapsedTimer &startup_time) :
 
 void Application::aboutToQuit() {
     _aboutToQuit = true;
+    setFullscreen(false); // if you exit while in full screen, you'll get bad behavior when you restart.
 }
 
 Application::~Application() {
diff --git a/interface/src/ui/HMDToolsDialog.cpp b/interface/src/ui/HMDToolsDialog.cpp
index a5e54fa546..88924f68d1 100644
--- a/interface/src/ui/HMDToolsDialog.cpp
+++ b/interface/src/ui/HMDToolsDialog.cpp
@@ -30,27 +30,27 @@ HMDToolsDialog::HMDToolsDialog(QWidget* parent) :
     QDialog(parent, Qt::Window | Qt::WindowCloseButtonHint | Qt::WindowStaysOnTopHint) ,
     _previousScreen(NULL),
     _hmdScreen(NULL),
-    _previousDialogScreen(NULL)
+    _hmdScreenNumber(-1),
+    _switchModeButton(NULL),
+    _debugDetails(NULL),
+    _previousDialogScreen(NULL),
+    _inHDMMode(false)
 {
     this->setWindowTitle("HMD Tools");
 
     // Create layouter
     QFormLayout* form = new QFormLayout();
+    const int WIDTH = 350;
 
     // Add a button to enter
-    QPushButton* enterModeButton = new QPushButton("Enter HMD Mode");
-    form->addRow("", enterModeButton);
-    connect(enterModeButton,SIGNAL(clicked(bool)),this,SLOT(enterModeClicked(bool)));
-
-    // Add a button to leave
-    QPushButton* leaveModeButton = new QPushButton("Leave HMD Mode");
-    form->addRow("", leaveModeButton);
-    connect(leaveModeButton,SIGNAL(clicked(bool)),this,SLOT(leaveModeClicked(bool)));
+    _switchModeButton = new QPushButton("Enter HMD Mode");
+    _switchModeButton->setFixedWidth(WIDTH);
+    form->addRow("", _switchModeButton);
+    connect(_switchModeButton,SIGNAL(clicked(bool)),this,SLOT(switchModeClicked(bool)));
 
     // Create a label with debug details...
     _debugDetails = new QLabel();
     _debugDetails->setText(getDebugDetails());
-    const int WIDTH = 350;
     const int HEIGHT = 100;
     _debugDetails->setFixedSize(WIDTH, HEIGHT);
     form->addRow("", _debugDetails);
@@ -65,14 +65,21 @@ HMDToolsDialog::HMDToolsDialog(QWidget* parent) :
     QWindow* mainWindow = Application::getInstance()->getWindow()->windowHandle();
     connect(mainWindow, &QWindow::screenChanged, this, &HMDToolsDialog::applicationWindowScreenChanged);
 
-    // watch for our dialog window moving screens. If it does we want to enforce our rules about what screens we're
-    // allowed on
+    // watch for our dialog window moving screens. If it does we want to enforce our rules about
+    // what screens we're allowed on
     QWindow* dialogWindow = windowHandle();
     connect(dialogWindow, &QWindow::screenChanged, this, &HMDToolsDialog::dialogWindowScreenChanged);
     connect(dialogWindow, &QWindow::xChanged, this, &HMDToolsDialog::dialogWindowGeometryChanged);
     connect(dialogWindow, &QWindow::yChanged, this, &HMDToolsDialog::dialogWindowGeometryChanged);
     connect(dialogWindow, &QWindow::widthChanged, this, &HMDToolsDialog::dialogWindowGeometryChanged);
     connect(dialogWindow, &QWindow::heightChanged, this, &HMDToolsDialog::dialogWindowGeometryChanged);
+    
+    // when the application is about to quit, leave HDM mode
+    connect(Application::getInstance(), SIGNAL(aboutToQuit()), this, SLOT(aboutToQuit()));
+
+    // keep track of changes to the number of screens
+    connect(QApplication::desktop(), &QDesktopWidget::screenCountChanged, this, &HMDToolsDialog::screenCountChanged);
+    
 }
 
 HMDToolsDialog::~HMDToolsDialog() {
@@ -96,11 +103,11 @@ void HMDToolsDialog::dialogWindowScreenChanged(QScreen* screen) {
     // if we have more than one screen, and a known hmdScreen then try to 
     // keep our dialog off of the hmdScreen
     if (QApplication::desktop()->screenCount() > 1) {
-        int hmdScreenNumber = OculusManager::getHMDScreen();
-
-        if (hmdScreenNumber >= 0) {
-            QScreen* hmdScreen = QGuiApplication::screens()[hmdScreenNumber];
     
+        // we want to use a local variable here because we are not necesarily in HMD mode
+        int hmdScreenNumber = OculusManager::getHMDScreen();
+        if (_hmdScreenNumber >= 0) {
+            QScreen* hmdScreen = QGuiApplication::screens()[hmdScreenNumber];
             if (screen == hmdScreen) {
                 qDebug() << "HMD Tools: Whoa! What are you doing? You don't want to move me to the HMD Screen!";
                 QWindow* dialogWindow = windowHandle();
@@ -154,42 +161,55 @@ QString HMDToolsDialog::getDebugDetails() const {
     results += "Application Primary Screen: " + QGuiApplication::primaryScreen()->name() + "\n";
     QScreen* mainWindowScreen = Application::getInstance()->getWindow()->windowHandle()->screen();
     results += "Application Main Window Screen: " + mainWindowScreen->name() + "\n";
+    results += "Total Screens: " + QString::number(QApplication::desktop()->screenCount()) + "\n";
 
     return results;
 }
 
-void HMDToolsDialog::enterModeClicked(bool checked) {
-    _debugDetails->setText(getDebugDetails());
+void HMDToolsDialog::switchModeClicked(bool checked) {
+    if (!_inHDMMode) {
+        enterHDMMode();
+    } else {
+        leaveHDMMode();
+    }
+}
 
-    int hmdScreen = OculusManager::getHMDScreen();
-    qDebug() << "enterModeClicked().... hmdScreen:" << hmdScreen;
+void HMDToolsDialog::enterHDMMode() {
+    if (!_inHDMMode) {
+        _switchModeButton->setText("Leave HMD Mode");
+        _debugDetails->setText(getDebugDetails());
+
+        _hmdScreenNumber = OculusManager::getHMDScreen();
     
-    if (hmdScreen >= 0) {
-        QWindow* mainWindow = Application::getInstance()->getWindow()->windowHandle();
-        _hmdScreen = QGuiApplication::screens()[hmdScreen];
+        if (_hmdScreenNumber >= 0) {
+            QWindow* mainWindow = Application::getInstance()->getWindow()->windowHandle();
+            _hmdScreen = QGuiApplication::screens()[_hmdScreenNumber];
         
-        _previousRect = Application::getInstance()->getWindow()->rect();
-        _previousRect = QRect(mainWindow->mapToGlobal(_previousRect.topLeft()), 
-                                mainWindow->mapToGlobal(_previousRect.bottomRight()));
-        _previousScreen = mainWindow->screen();
-        QRect rect = QApplication::desktop()->screenGeometry(hmdScreen);
-        mainWindow->setScreen(_hmdScreen);
-        mainWindow->setGeometry(rect);
+            _previousRect = Application::getInstance()->getWindow()->rect();
+            _previousRect = QRect(mainWindow->mapToGlobal(_previousRect.topLeft()), 
+                                    mainWindow->mapToGlobal(_previousRect.bottomRight()));
+            _previousScreen = mainWindow->screen();
+            QRect rect = QApplication::desktop()->screenGeometry(_hmdScreenNumber);
+            mainWindow->setScreen(_hmdScreen);
+            mainWindow->setGeometry(rect);
 
-        _wasMoved = true;
-    }
+            _wasMoved = true;
+        }
     
     
-    // if we're on a single screen setup, then hide our tools window when entering HMD mode
-    if (QApplication::desktop()->screenCount() == 1) {
-        close();
-    }
+        // if we're on a single screen setup, then hide our tools window when entering HMD mode
+        if (QApplication::desktop()->screenCount() == 1) {
+            close();
+        }
 
-    Application::getInstance()->setFullscreen(true);
-    Application::getInstance()->setEnableVRMode(true);
+        Application::getInstance()->setFullscreen(true);
+        Application::getInstance()->setEnableVRMode(true);
     
-    const int SLIGHT_DELAY = 500;
-    QTimer::singleShot(SLIGHT_DELAY, this, SLOT(activateWindowAfterEnterMode()));
+        const int SLIGHT_DELAY = 500;
+        QTimer::singleShot(SLIGHT_DELAY, this, SLOT(activateWindowAfterEnterMode()));
+    
+        _inHDMMode = true;
+    }
 }
 
 void HMDToolsDialog::activateWindowAfterEnterMode() {
@@ -199,23 +219,26 @@ void HMDToolsDialog::activateWindowAfterEnterMode() {
     centerCursorOnWidget(Application::getInstance()->getWindow());
 }
 
+void HMDToolsDialog::leaveHDMMode() {
+    if (_inHDMMode) {
+        _switchModeButton->setText("Enter HMD Mode");
+        _debugDetails->setText(getDebugDetails());
 
-void HMDToolsDialog::leaveModeClicked(bool checked) {
-    _debugDetails->setText(getDebugDetails());
+        Application::getInstance()->setFullscreen(false);
+        Application::getInstance()->setEnableVRMode(false);
+        Application::getInstance()->getWindow()->activateWindow();
 
-    Application::getInstance()->setFullscreen(false);
-    Application::getInstance()->setEnableVRMode(false);
-    Application::getInstance()->getWindow()->activateWindow();
-
-    if (_wasMoved) {
-        QWindow* mainWindow = Application::getInstance()->getWindow()->windowHandle();
-        mainWindow->setScreen(_previousScreen);
-        mainWindow->setGeometry(_previousRect);
+        if (_wasMoved) {
+            QWindow* mainWindow = Application::getInstance()->getWindow()->windowHandle();
+            mainWindow->setScreen(_previousScreen);
+            mainWindow->setGeometry(_previousRect);
     
-        const int SLIGHT_DELAY = 1500;
-        QTimer::singleShot(SLIGHT_DELAY, this, SLOT(moveWindowAfterLeaveMode()));
+            const int SLIGHT_DELAY = 1500;
+            QTimer::singleShot(SLIGHT_DELAY, this, SLOT(moveWindowAfterLeaveMode()));
+        }
+        _wasMoved = false;
+        _inHDMMode = false;
     }
-    _wasMoved = false;
 }
 
 void HMDToolsDialog::moveWindowAfterLeaveMode() {
@@ -256,3 +279,31 @@ void HMDToolsDialog::hideEvent(QHideEvent* event) {
 }
 
 
+void HMDToolsDialog::aboutToQuit() {
+    if (_inHDMMode) {
+        leaveHDMMode();
+    }
+}
+
+void HMDToolsDialog::screenCountChanged(int newCount) {
+    if (!OculusManager::isConnected()) {
+        OculusManager::connect();
+    }
+    int hmdScreenNumber = OculusManager::getHMDScreen();
+
+    if (_inHDMMode && _hmdScreenNumber != hmdScreenNumber) {
+        qDebug() << "HMD Display changed WHILE IN HMD MODE";
+        leaveHDMMode();
+        
+        // if there is a new best HDM screen then go back into HDM mode after done leaving
+        if (hmdScreenNumber >= 0) {
+            qDebug() << "Trying to go back into HDM Mode";
+            const int SLIGHT_DELAY = 2000;
+            QTimer::singleShot(SLIGHT_DELAY, this, SLOT(enterHDMMode()));
+        }
+    }
+    _debugDetails->setText(getDebugDetails());
+}
+
+
+
diff --git a/interface/src/ui/HMDToolsDialog.h b/interface/src/ui/HMDToolsDialog.h
index 4fe0dd626f..e3e5573533 100644
--- a/interface/src/ui/HMDToolsDialog.h
+++ b/interface/src/ui/HMDToolsDialog.h
@@ -28,14 +28,15 @@ signals:
 
 public slots:
     void reject();
-    void enterModeClicked(bool checked);
-    void leaveModeClicked(bool checked);
+    void switchModeClicked(bool checked);
     void activateWindowAfterEnterMode();
     void moveWindowAfterLeaveMode();
     void applicationWindowScreenChanged(QScreen* screen);
     void dialogWindowScreenChanged(QScreen* screen);
     void dialogWindowGeometryChanged(int arg);
-
+    void aboutToQuit(); 
+    void screenCountChanged(int newCount);
+    
 protected:
     virtual void closeEvent(QCloseEvent*); // Emits a 'closed' signal when this dialog is closed.
     virtual void showEvent(QShowEvent* event);
@@ -43,15 +44,20 @@ protected:
 
 private:
     void centerCursorOnWidget(QWidget* widget);
+    void enterHDMMode();
+    void leaveHDMMode();
 
     bool _wasMoved;
     QRect _previousRect;
     QScreen* _previousScreen;
     QScreen* _hmdScreen;
+    int _hmdScreenNumber;
+    QPushButton* _switchModeButton;
     QLabel* _debugDetails;
 
     QRect _previousDialogRect;
     QScreen* _previousDialogScreen;
+    bool _inHDMMode;
 };
 
 #endif // hifi_HMDToolsDialog_h