I want to install Guest Additions in a virtual Windows 7 running inside Ubuntu. The VirtualBox instructions are:
In the "Devices" menu in the virtual machine's menu bar, VirtualBox has a handy menu item named "Install guest additions", which mounts the Guest Additions ISO file inside your virtual machine. A Windows guest should then automatically start the Guest Additions installer, which installs the Guest Additions into your Windows guest.
How do I get to the "Devices" menu in the virtual machine's menu bar?