Norton is a huge resource hog. I use AVG free, it is great. And Norton killed one and almost 2 of my computers. It let stuff by it which shut it down on me.
Try testing without it in between, hooked directly to the modem.
So google them to see if you think they are necessary. As I stated unless you use them everyday, they are not necessary at start up. Like quicktime player, it is the worst for me. It slows things down a bunch. So I only want it to come on whenever I use it only. Otherwise it only sleeps.
These will make a big difference in your speeds.