Here's one that's been bugging me.
It's like a puzzle/quiz game from mid-nineties. In it, you try to, by solving stuff or answering questions correct, free a dude that's like a medieval joker from a medieval room. It also might be that some other dude is a joker and pops up to the screen from time to time. There's also a trap door or a box or something to which the dude falls if you mess up.
I was pretty young when I played is so this is all I've got. It might have come pre-installed with an IBM Aptiva PC or in a software disc package for it.
I'm wondering if this might be a slightly confused memory of Mindmaze, the game portion of Microsoft's Encarta encyclopedia. Bits of it are about right; meeting random characters (including jesters), the rough era of release, and the quizziness. The bit that doesn't match is your interpretation of the goal, though.