Advanced Mode allows you to create individual profiles. These profiles can be for various boot up styles. For instance you can create a bare bones boot up profile or one that will load items for development or one geared towards games. You can assign which profile you want to be loaded when your machine boots up. This feature is off by default. Toggling this either hides or displays additional menu items under the main File menu item. You can have Startup Guru prompt you for a profile by checking the Prompt for profile checkbox. This will allow you to select the desired profile when your machine is booting up, rather than having to decide before you shut down.