A lot of viruses get into your computer by exploiting (taking advantage of) loop holes or security vulnerabilities in existing "friendly" software.
One very common piece of software is one that is on most computers out there... Java. No, not the coffee that you spilled on your keyboard countless times, but the programming language that is used by lots and lots of software, and lots and lots of websites that we visit and use every day.
Java is constantly updated (which is good), but that's because hackers are always looking for and finding exploits (which is bad).
So if you haven't updated your Java lately, do it: go to http://www.java.com/
But, you can't just upgrade Java, you also have to get rid of the older versions which have the vulnerabilities. So to do that, Oracle has provided this nifty tool for you to run AFTER you install your new fresh cup of Java: http://java.com/en/download/uninstallapplet.jsp
This tool will help you locate and uninstall the old version.
The Tech Whisperer is an IT Manager on the east coast with over 25 years of experience in IT, a self-proclaimed autodidact, and a happy father of 6 future world leaders.