But if you didn't run windows you would have a OS where you can't easily install spyware without the user knowing it, thus no need for ad-aware.

Why does anyone stick with a OS that crashes daily, is easy to get viruses on, it's easy to install spyware you don't know about, IE allows popups all over the place and you have to BUY and run a outside program to get rid of them, the mail program STILL in 2002 allows people to send you programs that RUN INSTANTLY without asking you anything, you have to worry about how many windows you have open or else blue screen bye bye and they still don't fix any of this.

You don't know what it's like to have a crash & virus free computer till you try it.