I'm running Window XP. Since installing Norton 360 my computer runs slow, locks up, and when I try to run Live Update I get the error message that it's already running in another application. Of course, I've tried Norton's help folks but of course, their English is quite bad and four people have given me four different answers, none of which work. Has anyone else had this problem? My son installed it on his computer and is having the same slow, lock up problems.