First, do a search on your PC for any folder called "symantec". You'll find it's left in "Program Files" and "Documents and Settings". Delete them and any others that show up in your search. You'll probably see that Live Update is left behind, so delete it too.Then you have to go into the registry and delete the
load of reg entries that are left, search for "Symantec", "Norton", "NIS" and "NAV". Delete them.
That's it, but it can take a while to trawl through the reg. Also, some of the registry keys left are "legacy" entries which cannot be deleted normally until you right click on the entry and change the permissions to allow them to be deleted.