One means of protecting your computer is a software firewall. This is a program which intercepts traffic between your computer and the Internet, and checks it before letting it through. McAfee Personal Firewall is designed for Windows systems, and according to the automatic port scanner at grc.com, it's pretty effective at walling off a system from potential harm.
Of course, some Internet communication must be allowed, or you wouldn't be able to browse the Web or send e-mail. Personal Firewall alerts you whenever a program attempts to access the Internet from your computer, and lets you decide whether to allow, or block, that application in future. It's easy to adjust the permission status of applications, but unfortunately there's no way to put a program on that list before it makes an Internet request.
There's a wide range of options to specify which network protocols may be used to talk to your machine. When the firewall detects an attempt to use one of the protocols you've disallowed, the computer chirps to alert you. However, there's no way to turn off the alert sound, and tracking through Windows' jungle of network protocols to find the one that's driving you crazy by setting off a chirp every five minutes can get unpleasant.
The annoying issue of the alert sound sent me looking for advice on how to turn it off. Unfortunately, Personal Firewall is backed - if that's the word - by some of the most annoying and least useful online support I've ever seen. It seems customer service has been replaced by the need to collect e-mail addresses for marketing.
To access the help section of McAfee's confusing Web site, you must hand over your e-mail address and choose a password (as if we didn't have enough useless passwords in our lives already). You then have to wait for a coded link to arrive in your e-mail before you can finally enter the support site, where you are offered the chance to opt out of six different mailing lists. Need an update? Surprise - you have to enter a different registration code and password.
Having said that, McAfee Personal Firewall appears to be able to do its job well if you're prepared to fiddle with the settings until it's blocking or allowing all the right things. However, the support Web site could put off some users.
McAfee Personal Firewall
Distributor: Network Associates
Phone: 1300 361 367