Here is how to normally pop out and return the Control Dock window:
Click the windows icon to make the Control Dock a separate window.
When the Control Dock is in a separate window, double click on it to return it to the ARD GUI.

If you no longer see the Control Dock at all, even after restarting ARD, you will need to edit the Windows registry. Agile Designer saves color schemes and styles in the registry, which includes the Control Dock.
NOTE: Please take a backup of your Windows registry before making any changes to it.
Steps to edit the Windows registry and return the Control Dock to ARD:
1. In the Window's search, type in 'regedit' and Enter to launch the Registry Editor.

2. Locate this Registry key on the left pane: HKEY_CURRENT_USER\Software\CA Technologies\AgileDesigner

3. In the right pane, look for the 'pathExplorerState' entry and delete it.

4. Restart Agile Designer and the VM/Server where the registry edit was made.
5. The next time ARD is launched, it should go back to the default settings and the Control Dock should be visible.