Think your PC is 'safe' online? Think again.

While most Internet users think they are safe online, they're not, according to a new study released Wednesday by America Online and the National Cyber Security Alliance. In fact, about 80 percent are exposed to common Internet threats, the study found.

More than half of the participants either had no anti-virus protection or had not updated it within the last week, researchers found. About half did not have a properly-configured firewall, and four in ten didn't have spyware protection. Taken collectively, more than 4 in five consumers lacked at least one of the three types of basic protection.

Still, 83 percent told researchers they were "safe from online threats," the study found.

The results mirror a similar study conducted last year by AOL and Cyber Security Alliance. The sweeping study is thorough; researchers follow-up survey responses with in-home visits, and technicians inspect consumers' PCs. Among the key findings -- consumers often falsely believe their computers have up-to-date Internet pest protection when they don't.

"People have a false sense of security," said Tatiana Platt, senior vice president at AOL.

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