In 10-inch skillet, cook beef over medium-high heat 5 to 7 minutes, stirring occasionally, until brown; drain. Stir in taco seasoning mix and water. Cook over medium heat 10 to 15 minutes, stirring occasionally.
Heat taco shells and flour tortillas as directed on packages.
Spread 2 tablespoons heated refried beans on each flour tortilla. Place hard taco shell on center of flour tortilla and gently fold tortilla sides up to match taco shell sides.
Spoon 2 tablespoons beef mixture into each double-layer taco shell. Top with salsa, lettuce and cheese. Serve immediately.