Use a free AV such as Avast or AVG free. One real time spyware protector such as Spyware Terminator (free) and the inbuilt Vista firewall or your router firewall will be more than enough. Do not pay for protection as there is no earthy need for a home user to pay. Get an 4 or 8Gb memory stick (£20) and don't forget to backup your important files. Don't get too much protection or you will get confused or go batty.