http://www.malwarebytes.org/

http://www.avg.com/us-en/homepage

http://technet.microsoft.com/en-us/library/cc875811.aspx (Windows XP Firewall).

And run firefox with adblock plus. Make sure Adobe Flash and Java are updated regularly!


The last one is the most important. Flash and Java's web plugins are known vectors for attack.

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-Typos courtesy of my mobile phone.