That looked just the job but I have checked right through the list of programs on "Uninstall or change a program" . The only Security programs that I have deliberately installed are AVG (free version) and Spybot S&D. Norton was uninstalled and seems to have gone and there is something called Infineon Security Platform which is not initialised. I have not yet found out what this is or if it is a good thing to have.
On this computer (XP desktop) I run AVG, Spybot S&D, Spywareblaster and Adaware and hope to do likewise on the Vista machine.