I generally agree with Threadweaver... generally speaking, if something legitimate actually needed it and you were missing it, it should pop up a notice stating you need it, and either ask you to download/install it, or ask you if it can get it and download/install it.
Generally, I like installing everything a system needs and only what it needs at time of reset, but sometimes you just cannot know, but in any case if needed at all, should not be a big deal.