A reply from my son in South Bend:
chris.gardner@nsi1.com

Excellent suggestions and links from Bill - a "defense in depth" strategy is best when securing your computer. On a corporate network it means that multiple hardware and software tools will be used to secure the network - on a home PC it means that you may need to use a combination of software tools (and a hardware firewall) to secure your PC.

Here's a great link for overall PC security:
http://www.pcmag.com/article2/0,1759,1621066,00.asp

The biggest issue that I see with home users that have broadband (cable/dsl) is that they do not have a hardware firewall behind their cable/dsl modem as a first line of defense. Many of the automatic worms on the net can be shunned by this firewall which effectively hides your computer from others. Linksys devices has been a favorite of mine because they are easy to set up. They all usually include a 4-port switch (if you just have 1 computer that's fine, you still need a hardware firewall), many have wireless options (you need to set up the wireless security if you use this!!) and you can get one for $30 - $100.00.

My home setup - cable modem, linksys 4-port broadband router with wireless, 1 Windows XP computer, 1 XP laptop, 1 Windows 95 computer. Zonealarm free version (software firewall - lets you know what is trying to get OUT) on all computers; AVG Anti-virus free version on all computers (and I'll periodically run the Trend housecall - great suggestion); Ad-Aware free version for spyware (although I'd use Spybot Search and Destroy as another detector if I thought I had an infestation). WindowsUpdate set to notify me of critical downloads. I route all of my personal email to Yahoo mail (and their free anti-virus and spam tools) and DON'T use Outlook express. Don't use an additional popup blocker (have never had problems with them). Instead of Internet Explorer I use Firefox from mozilla.org and it does have a pop-up blocker. While it certainly had had a few security issues, it has not had the plethora of problems that IE does. I still keep IE around because there are compatibility issues with some sites.

Anti-virus tip - if you are infected and need to run multiple AV's to ferret out the problem, many of the AV sites offer trial versions of their "Enterprise" product that you can use in a pinch.