In a medium bowl, pour boiling water into gelatin and stir 1 to 2 minutes, or until gelatin is completely dissolved. Refrigerate until slightly thickened; stir frequently.
In a large bowl, mix yogurt and salad dressing with wire whisk until smooth. Add thickened gelatin and continue stirring until smooth. Gently fold in whipped topping. Pour mixture into crust. Cover and refrigerate for several hours or until firm. Drizzle preserves over pie immediately before serving.