I couldn't remove corrupt Norton from the Add/Control panel. Fortunately, Symantec provided a free tool that lets you uninstall Norton with a one button click. The strange thing is if you reinstall it, you don't have to download everything all over again. Apparently, the uninstall tool preserves your DAT files.
(Denny Crane: "Sometimes you can only look for answers from God and failing that... and Fox News".)