Docking Tab (Options Dialog Box)
Allows you to choose which windows you want to be dockable. A window is docked when it is attached or "anchored" to one edge of other dockable or application windows. When you move a dockable window, it "snaps" to the location. A window is not dockable when you can move it anywhere on the screen and leave it there.
Select the windows you want to be dockable and clear those that you do not. Any, none, or all of the windows in the list can be docked.