An even better way to stop virus infecting your machines is buy a mac. The 5 years I've been using them never had a single one. A fellow workmate brought a brand new windows machine with anti virus software logged on to the internet and got a virus straight away !! The bottom line is Windows has more holes than a tetley teabag and is always going to have problems that way. Its not just the hackers at fault, the billion dollar company microsoft is it should do better to protect its machines.