Every broadband user needs a decent firewall. Going online without one is tantamount to suicide. Windows XP and higher has a respectable firewall, but it can be improved upon. Luckily there's a good free one in PC Tools Firewall Plus from the makers of Spyware Doctor. PC Tools Firewall Plus is much more than a simple firewall, and has an expert mode with more bells and whistles that can be configured. If you prefer the quiet life, PC Tools Firewall Plus can deal with most alerts for you automatically. It's compatible with Windows 2000/XP/Vista. More: PC Tools Firewall Plus