Well if your sure you need it deleting then you just Run: Regedit and do a Ctrl+F to do a search and copy and paste any part of that reference into to search box. When it finds all that info you just highlight it and press the Delete key and select Yes to delete it.
I too run Norton IS 2008 and after reading the thread took a chance on deleting in Safe Mode, after saving the backup, which was successful. Did another scan, came up with another entry referring to Symantec, deleted that, now all clear and Norton AntiSpam in Outlook Express still works fine, so looks ok.
Many thanks from a satisfied user, donation heading your way!