You can cure about 99.99% of virus woes by getting rid of IE. There are so many browser vulnerabilities and exploits for them that no AV product can keep you safe if you surf the web a lot. Download a copy of Firefox and the add-on NoScript. NoScript has a white list that you build for sites you trust. All other sites are blocked for JavaScript, flash, and all the other little nasties that spread malware. If there is something you just have to see, you can temporarily allow scripts for that site. I use Firefox/NoScript exclusively and haven't had a virus or adware installed on any of my computers.
Of course, I do most of my web surfing with a Linux PC, which is sort of cheating.
Using "NoScript" has the same effect as disabling ActiveX and Javascript in IE. You can use the zones to insert trusted sites. Configured in that manner, IE will not be any more vulnerable than FireFox is. Just FYI.
Most of the problems with IE stem from the default security settings Microsoft chose.
I do not use anti-virus or software firewalls and have never had a virus or spyware either.
