I just received a birthday gift of a MSI Wind Notebook which uses Windows XP. My main computer is an Apple IMAC which I have been using for more than a year (my old Dell crashed). Therefore, I have forgotten most of necessaries for using IE and Windows. At home, I am behind a router and have a WIFI setup...courtesy of my son-in-law. Do I need to install AVG or ZA or perhaps someother means of protection? This would be for those times when I am using it when travelling. Suggestions are appreciated.