It goes without saying that antivirus software and a firewall are a necessity. But these alone won't protect you against today's malware. Here are four simple and very important changes you can make that will keep you safer online and off.
1. Switch to Firefox with NoScript. Just Firefox alone won't help - the magic is the NoScript addon (which only works with Firefox). The NoScript addon is free and works by blocking all javascript from sites you haven't pre-approved.
2. Remove Adobe Reader and Acrobat and switch to one of the alternative (and safer) free PDF readers. Be sure to uninstall Reader and Acrobat, as just their mere presence can leave your system at risk. If you absolutely cannot switch, at the very least tweak the settings in Adobe Reader/Acrobat to make them safer to use.
3. Disable autorun. This built-in feature of Windows lets backdoor trojans spread as if they were worms. Disabling autorun prevents this spread, making it easier to isolate and defeat the malware.
4. Disable Java in your browser. Java has outpaced Adobe Reader/Acrobat as the most frequently encountered exploits on the Web. Java (not to be confused with javascript) is very seldom needed when surfing the Web. To stay safer online, here's how to disable Java in Firefox and disable Java in Internet Explorer.