1.Which is the best antivirus among Eset Nod 32(ver 4),Microsoft security essentials and Avast? (or) any better one other than mentioned here. 2.Which is the best firewall among Comodo free firewall,Online Armor free and Windows firewall?(or) any better one other than mentioned here. Please consider the effectiveness in performance and security of the system without affecting system performance exclude customer support. 3.Also suggest some portable scanners for the system.