How to bring back menus is VirtualBox
Solution 1:
You can go back from full-screen mode in a VirtualBox guest OS by pressing the keyboard shortcut Right Ctrl+F. Note that the main menu bar is hidden in full-screen mode. You can access a popup menu that has the main menu bar's entries (as shown in the 2nd screenshot) by pressing Right Ctrl+Home.
To reenable the Toolbar in the VirtualBox application right-click on the bottom panel and check the checkbox next to Show Toolbar as shown in the following screenshot.
