check to make sure it isn't in your public folders... I searched and researched, I went into the registries, deleted all norton products in the registry keys as well as in windows currentversion run & runonce (if it in there) and then discovered when I deleted it from the runonce folder within the registry under microsoft windows for local user, I saw the window pop right back up and the key automatically reappear after I just deleted... that is when I SAW where the program was hiding... it was hiding under user\public\downloads (or public downloads). I deleted it from there, and then went back to the registry and deleted it from the keys again that reproduced themselves.
Then I went to downloads just for me (being I'm the only one that uses my laptop) and removed any other downloads from norton (such as the "removal tool") just to be certain.
After that I restarted my computer and so far... I haven't seen anymore splash screens for installing norton...