Are 1996 Ford Explorer engines compatible with Windstar engines?

No, 1996 Ford Explorer engines and 1996 Ford Windstar engines are not directly compatible. While both were Ford vehicles from the same year, they used different engines and engine mounts. The Explorers generally used larger V6 or V8 engines, while the Windstars used smaller V6 engines. Even if the displacement were similar, the mounting points, accessories, and wiring harnesses would be completely different.