Firewalls do not guarantee that your computer will not be attacked

Though properly configured firewalls may effectively block some attacks, do not be lulled into a false sense of security. Firewalls primarily help protect against malicious traffic, not against malicious programs (i.e., malware), and may not protect you if you accidentally install or run malware on your computer. However, using a firewall in conjunction with other protective measures (e.g., antivirus software such as Total Defense and safe computing practices) will strengthen your resistance to attacks.