why is google toolbar being pushed to my computer when I install flash?

Why does everytime I install some software, free software but often essential, I am being forced to download something without my permission and no option to opt out, I don't want google toolbar but for some reason its being forced on me? If this keeps on happening I will abandon the use of google and go to some other search tool, I hate bing and yahoo who try to force you into there use there search tools, aswell as ask.com... but really does google need to even bother trying to make me use it? I will use it as long as they stop trying to control my use of the internet.