It's almost inevitable for those folks who spend a great deal of their time checking out the latest news, funny videos, Facebook updates or Farmville crop rotations that a small virus or piece of adware will slip through the security filters. Thankfully, several solutions exist for free, online!How to Run a Free, Online System Virus / Malware Scan and DiagnosticThere are several options available to users looking for a free virus scanner online:Trend Micro HouseCall: The quick, dirty, and efficient solution, Trend Micro's HouseCall scanner is the most reputable and effective virus scanner on the internet. Being one of the first internet based virus solutions, HouseCall has advanced over the years to include one of the most comprehensive virus databases while retaining the speed and efficie