Firewall discussion board | Computer Science homework help

Visit the following websites for a list and brief explanation of free firewalls that are available for Windows XP, Windows 7 and Windows 8.

http://www.techsupportalert.com/best-free-firewall.htm

http://www.techsupportalert.com/best-free-firewall.htm#Comodo_Firewall

Which one of these firewalls would you choose given the list of firewalls that are listed?
Explain why.