Avira Internet Security Free Download

Avira AntiVir Personal - FREE Antivirus

and if you need more protection then try Avira Premium Security Suite

Do you surf the Internet, shop online, communicate by email or do your banking online? The Avira Security Suite protects you for this and includes a Firewall, AntiSpam, ParentalControl and a backup function in addition to the award winning virus protection.

Kaspersky's good too