We use Windows Defender and Avast!. The Avast! virus protection is free and you just need to sign up for it online. The combination of both of these programs has done us very well over the past 3 years, with very few buggies that have gotten past these systems. Either way would reccommend that you don't go online till you have some form of virus protection, as you leave yourself open to every virus, spywear, etc on the net.