First off you dont need an antivirus software you need all in one internet security software these days with firewall, anti phishing, anti hacking, adware and spyware protection with antivirus...... I have used and recommend to anyone that asks: 1) Bitdefender Internet Security - awesome protection, daily updates and so easy to use 2) Kaspersky Internet Security 3) McAfee Internet Security w/ Ad-Aware Pro Depends what you are doing but if you do the net heaps then i suggest you run lavasoft Ad-aware Pro a along side one of the above all in one software for the max security Works great for me