I would highly recommend Avast..its used by alot of the major corporations,so much so that avast issue it to home users for free to try and catch virus and malware before it spreads .
download it ,register it for free and it will be yours for as long as you want to use it.I have been using it for 6 years and never had one single virus or malware since ive had it.
http://www.avast.com/en-gb/index
and a review of it.
http://download.cnet.com/Avast-Free-...-10019223.html
150,000,000 cant all be wrong.