I bet it'll run a whole lot faster with Norton turned off (or not installed) than it will with it on.
Every PC I've ever put Norton went into slow-motion like an attorney waiting to see who'll pick up the check. It loads a ton of system hooks, DLLs, and extra stuff that just loads the system down.
So, I did ask hubby about the Norton, and he says I'm not been totally ummmm......accurate, when I say this thing responds like lightning.....that I've slowly become accustomed to the 'slow down'. He says it was 'the path of least restistance' at the time, and has just 'gone with it', but agrees with your take on Norton an will explore other options. He said the latest update, which included Norton ghost, was like adding a lead weight to a sinking swimmer.