I'm sure there are good reasons, but I wonder why we have to be constantly bugged with virus and spam prevention software at the level of each pc. My computer is constantly screaming at me to update anti spam and anti-viral software. Don't all virus containing programs have to exist on the internet somewhere, or pass through the internet on its way to my computer? Then why can't anti-virus software be placed on the internet host machines to intercept them BEFORE they get to my machine? Seems like that would be a lot more efficient and cheaper way to fight virus software. Instead of millions of people having to pay millions of dollars for very annoying software that has to be updated every time you access the internet and for which you have to pay for every year, the problem would be handled by the service providers and internet infrastructure.