I can't say specifically with Norton as I use the ZoneAlarm firewall and anti-virus, but I know that ZA's "TrueVector" service loads very quickly before Windows starts, and before the network connection is enabled.
Some years ago I was shocked when I realised that the networked enabled so early in bootup, but then found out that TrueVector also loads early on to prevent hackers from gaining access during this vulnerable period.
All good firewalls will have a similar service, and Nortons ins one of the best.
I have a Vista Home premium 32 bit with Vista SP 2
Its a Dell desktop PC. Configuration as
PC>>DSL MODM (no router)>>>>>Phone/DSL wall jack
The DSL line is always connected. So when I turn my computer on, as it starts up it will also connect to the internet
Now my qustion is, how do I know that my internet Security (Norton) loads up and turns on BEFORE my PC actually connects to the internet?