One of the most popular technical questions of this decade is, "I have antivirus, so how did I catch this virus?" In the digital world that we live in, there are wolves in sheep-clothing everywhere.  Take some time to learn good web surfing practices like the following examples: 
Don't be tricked into clicking advertisements or outside links - "You've won a new TV!  Click Me!" - pay attention to where the link is going to take you before going

Second - Don't open emails with generic titles, claiming to be from financial institutions, or from unknown people in general - Most spam ends at "annoying", while a simple email stating "update your Paypal info" can be detrimental.

Third - If you see previously unknown applications running on your PC asking you to purchase them or telling you that you have a virus, ask someone.  They may know that it is legitimate, or they may not have seen it before also.  "Crimeware", as they call it, is rapidly growing and is very difficult for antivirus applications to detect them since they cause no direct harm as well as do nothing to your PC except open a window asking you questions.

Remember - You are the first line of defense in keeping unwanted programs from infecting your PC.  Practice these simple, safe steps, and you can save yourself and your business both time and money.   Happy (and safe) surfing!

Related Product Information: Web and email filtering.