There are always new viruses coming out and if you are always downloading information then you need to get antivirus protection.  Many people learn the hard way about using antivirus software protection.  Often, they decide they do not need it, and then they get a virus and their computer gets destroyed.  Many times they spend money on the wrong antivirus software.  There are many antivirus software programs on the market and some of them do not work or they just load your computer with spy-ware.  The avg download will keep your computer safe against viruses and you will not get added spy-ware from using the software.