I've searched every computation of educational pig games for Windows so I've wound up here. I had three of the games in this series.

One was the human body, and the main character (who was a bipedal pig or looked very much like one) had to travel around and help various parts of the human body and answer questions. One of the first ones he met was a talking tongue who would usually ask questions about taste buds. Then he would meet a pair of ears, one of which couldn't walk without falling down, and you had to say which area of the ear correlated with balance. Eventually you would wind up answering questions about red and white blood cells, etc.

The second game in the series was Plants and Animals, and you had to go on a journey to a farm in order to pick up plants to save your family's farm, where all the crops were dying. Along the way, you had to answer questions about plants and animals in order to get past the creatures who were blocking you. I remember a grasshopper/cricket being in the game, as well as a boar.

The third one I had was something along the lines of "Back to the Future" for the title. It was focused more on technology and it had questions like why manhole covers were round and what shape roads were. I don't remember the overarching plot of that one, besides I think he wound up in a time machine or spaceship and had to figure out how to get home.

The main character's name was always in the title, along with whatever it was focused on, so it would be things like "X goes Back to the Future" or "X explores the human body", I think.