I can't remember what this computer game is called?

I used to play an educational computer game when I was in elementary school or so (I'm 20 now). It had to do with a witch somehow? I remember there were leters in a spider web and you had to collect them. There was also a challenge where you had to mix ingredients in a cauldron to make a potion that were rich green, purple, and orange. There were keys that you found also in a house? I really liked the game and just can't for the life of me remember what it was called. Does anyone know what I'm talking about?