I like Norton Internet Security. But sometimes it’ll be using 50% of CPU time on my laptop, which means the fan is whirring constantly. (You can check this by clicking Performance on the main screen.) After some poking around I discovered much of this background activity is Norton optimizing the disk and other non-essential activities.
Here’s how to turn that off. Click Settings on the main screen, then Miscellaneous Settings, then click Silent Mode on. It’ll ask for long you want it off for, choose 1 day. (You do have to reset this each day.) Norton will now stop going berserk in the background.