Maybe the safest thing to do is take the computer away from him 
I have a lot of those anti spyware progs. Since I use alternative browsers like Firefox and Opera, they only find a few tracking cookies now and then. My provider gives me Norton Security 2005 for free so I use that (antivirus + firewall).
I’ve noticed I get more spyware with Firefox than I used to. I think as it gets more popular, so does the spyware for it.
Bare in mind that when firefox was new there were no spyware and other little things aimed for it. So it was inevitable that in time spyware would popup, along with popups targeting the browser.
My suggestion for firefox users would be the extentions ad-block, to block any adds that firefox doesn’t kill on it’s own and also “no script” it blocks java-script on all sites by default. with options to allow/temporary allow the site you are on.
Did FireFox avoid those annoying pop-up ads Internet Explorer normally shows?
And you’re wrong, broken-sword. There are viruses written for Macintosh. (I assume you meant the Operating System Mac.)
Did FireFox avoid those annoying pop-up ads Internet Explorer normally shows?
They did. Although some sites now have ads made for firefox, but that’s what the adblock plug-in is for. I haven’t have one popup since i started using that, it also lets you remove ads in pages that aren’t popups - like flash ads and image ads.
It allows you to use the wildcard * as well so you can block full ad servers like doubleclick.com
I’ve got the popup blocker add on for firefox, but there still always seems to be a tracking cookie or a neglegable object when I check my computer every couple weeks.
Oh well, no system is perfect I guess 
Absolutely correct, Josh.
The Firefox adblock extension is great! I wish Opera had such an extension, since it has all other stuff I wish but have to install in Firefox. I love the wildcard function of adblock, because this way I avoid a lot of ads on sites I visit for the first time. I do have popups now and then on firefox, but those are site related so not considered spyware (nothing is installed on my PC).
Some people say Opera is faster and better than Firefox. It has some nice stuff, but for me personally the extentions and ability to config firefox pushes it past Opera. Also having tweaked with the settings I find even without caching FF is faster shrugs
Still opera is a nice browser which I would most likely be using if FF wasn’t around