This menu allows you to manage GIMP windows dialogs:
The “Windows” menu name is not well adapted to the new single-window mode. Nevertheless, its functions concern multi and single modes. Its display may vary according presence or absence of images and docks:
Recently Closed Docks: this command opens the list of the docks you have closed recently. You can reopen them by clicking on their name. Please note that isolated windows are not concerned.
For more information about docks, please see Dialogs and Docking.
Dockable Dialogs: this command opens the list of dockable dialogs. Please refer to Section 2.3, “Dialogs and Docking”.
Toolbox: clicking on this command or using the Ctrl+B shortcut, raises the toolbox usually together with the tool options dock. Note that in single-window mode this usually doesn't have any effect since the toolbox is part of the main window.
The list of open image windows: clicking on an image name, or using the Alt+Number of the image shortcut, makes the image active.
The list of open docks: in this list, docks are named with the name of the active dialog in this dock. Clicking on a dock name raises this dock. Note that in single-window mode only docks that are not part of the main window will be shown here.
Hide Docks (Tab): this command hides all docks (usually to the left and right of the image), leaving the image window alone. The command status is kept on quitting GIMP and will be in the same state when GIMP starts.
Show Tabs: in single-window mode this command changes whether or not to show the tabs with all opened images. By default the tab bar is shown, but you can hide it if you don't need it and want to use the extra screen space. In multi-window mode this command is disabled.
Tabs Position: In single-window mode you can use this command to choose the position of the tab bar that shows the loaded images. By default the tab bar is located at the Top, but you can change this to show it at the Bottom, Left, or Right. In multi-window mode this command is disabled.
Single Window Mode: when enabled, GIMP is in a single window mode. Please see Single Window Mode.