It is a good idea to have one installed. Connecting to the Internet
without a firewall is like leaving the keys in your car with the engine
running and the doors unlocked while you run into the store. Although
you may be able to get in and out before anyone notices, someone may
take advantage of the opportunity. On the Internet, hackers use
malicious code-such as viruses, worms, and Trojan horses-to try to find
unprotected computers. A firewall can help protect your computer
against these and other security attacks.