(OS: Windows 8 Pro)
Whilst I wait for Norton support to contact me re Norton 360, I have enabled Windows Defender. I notice I have to manually check for updates, rather than have them automatically installed. Also, if I don't have the actual application open (i.e. Start > All Programs > click on Windows Defender) is it still operating?

Above are my current Windows Update settings. I notice that updates will be automatically installed during the maintenance window, but I don't have a specific time for Windows to perform maintenance. Also, updates only download while on un-metered internet connection. How do I change this, so they install automatically, and download whenever they're released, regardless of my internet connection.
Do Windows Defender updates get downloaded automatically via Windows Update?