How to install Older PC Games on Vista?

Okay, I have 2 Older PC Games that I want to download on my Vista Laptop. I know that there is a way to do it, I just can't remember how. I did it before on my XP and I think on my Cousin's Vista. However, now I don't remember. The Games are called "Geometry Blaster" and "Carmen Sandiego's Great Chase Through Time" if that matters. So, How to install Older PC Games on Vista? and I've heard of Emulators. Like, Do I just like search for one and download and then I'm done or what?