Ow.. That's not fair at all. I don't have those problems, only anoying little brothers who download virussus into the computer. Since a few months they ask me whether they can download something or not, that helped. We had only had one virus since.
But as you are the only one using your computer, I don't know why it happens(because I think you know what you can or cannot download). It's kind of unfair.
The fact: Nothing goes the way you want it to.
I have got different opinions on that(Schizophrenia??(nah, kidding)).
I think it is correct that nothing goes the way you want it to, because we humans can't make things perfect.
But... Things could work out the way we want to, if we did everything perfect and securly. Like cleaning up everything, or watch where you walk all the time, etc. But.. we humans are too lazy to keep on doing things perfect, so it's our own fault(I'm not blaming you or something)
Heh.. I am a bit weird..