Because the task isn't running under the user you're logged in as, it won't show in Task Manager unless you tell Task Manager to show tasks from all users (button at the bottom of the processes list).
As for the rest... not sure what you mean by notifications list? Perhaps try a restart?
By the way, a simpler method might be to forget the whole scheduled task thing and just copy a shortcut to the Start menu Startup folder (as other posters already said), and then under the properties of that shortcut, say to always run with administrative privileges.
You will probably get a UAC warning every time you login but it may work better.