You know how to set up the configuration?
Most commercial firewall products, both hardware and software, are configured to ensure acceptance from most users. For each different firewall you need to read and understand the accompanying documentation to determine if the default settings on this firewall are guaranteed to meet your needs. In addition, you must pay attention to warnings about the current virus and worm because sometimes it includes information about the limitations that can be enforced through the firewall.
When properly configured firewalls it can withstand some attacks, but you should not be subject to some security flaws. Firewalls can give the computer a fairly solid protection but are not completely guaranteed to be attacked. Specifically, a firewall with uncertain protection does not prevent malicious programs from running on the computer. However, using a common firewall with security checks (such as anti-virus software and safe computer operations) will help the computer to resist all attacks.