No one product is going to be 100% successful in always catching all infections.
You need the following:
1) An antivirus program
2) An antimalware program, and
3) A firewall.
Some programs do only one of the three.
I'm currently using Norton 360. Norton has had a bad rap because older versions used to chew up vast amounts of system resources. The current 360 version does not appear to be so much of a problem for me.
I have used Webroot - Great product, but the worst customer service of all that I have tried.
I have used McAfee - Pretty good, but it let too many infections fly by.
I have used Panda AntiVirus - It's like Having a Kung-Fu Panda on your PC. No complaints (yet)
I have used Avast and AVG - The motel 6 of of protection.
I have used Zonealarm Firewall - Very powerful, but almost too powerful for the novice user.
I have used Windows Firewall - Is this thing working?
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Here's how I currently keep my PC Clean:
* I have Norton 360 running all the time. It has built in antivirus, built in malware detection, and a built in firewall.
* I installed and use McAfee Site Advisor (a free download). It will check web sites for known infections and warn you before you click.
* I NEVER use Microsoft Internet Explorer unless absolutely necessary.
* I use either Firefox or Safari as my web browsers.
* I update and run a Malwarebytes scan every 2-4 weeks.
* I update and run Panda Activescan once a month.
* I update and install a custom hosts file every 2 months.
http://www.mvps.org/winhelp2002/hosts.htm