I have a fairly new Dell and everything works fine until Norton Internet Security starts up. It slows my computer into uslessness and I have to shut it down. I turned off the auto update, which helped, but still it seems to have a mind of it's own and I cannot tell what it is doing or what kind of schedule it is on. It is so bad, that if I cannot get this resolved, I will not buy another PC and switch to Mac. I do not have any other security software installed. I purchased Norton Internet Security on-line and download the update annually.