I realize I'm late to the party but just throwing my 2 cents in: Every pc and laptop I service/sell gets the Microsoft Security Essentials program you already have because - hey it's a free updated antivirus. They update it a lot and its pretty good. What it doesn't do well is eliminate Spyware. Most Spyware is not considered a virus and is ignored by MSE, Norton, McAfee, etc. I ALWAYS install MalwareBytes Anti-Malware on my systems. Free scanner that updates a lot. It's not an active scanner so you have to run it yourself. I run mine 2-3 times a month as I use my own computer constantly. Works much better than Spybot IMHO. You should check it out. http://www.malwarebytes.org/