Preheat oven to 425*. Place pizza shells on 2 pizza pans or cookie sheets.With back of large spoon, spread 1/3 cup of dressing evenly over each shell leaving 1/4-inch border.Over dressing on each shell, sprinkle 2/3 cup cheese and half of corned beef and sauerkraut. Sprinkle remaining cheese evenly over sauerkraut.
Bake pizzas 15 to 18 minutes or until cheese browns and crust is crisp. Transfer pizza to large cutting board;cut each pizza into 6 slices to serve.