I very rarely have a problem with popups/virus infections/trojans etc. I hope the info below will help those with this type of problem.
Keep up with the windows critical updates.
Keep your Anti-virus software up to date and run it at least weekly.
Be very cautious about what attachments you open that come in your email.
"Free Software", especially that which is offered from a website usually Isn't free. There is almost always a catch. Usually adware or spyware is downloaded at the same time without your knowledge.
Like Ric said ZoneAlarm is a free software firewall, but if you are on a broadband (cable or DSL) connection and you have a router between your PC and the Internet then a software firewall isn't really necessary.
With that said, even though I haven't experienced any popup ads on PB, LOTS of otherwise reputable sites (Fox, CNN, etc)do employ popups as a source of revenue. My previous note about the Google Toolbar applies. It will stop 99.99% of all popups.
