Cook pasta according to package directions.
Meanwhile, in a skillet, cook beef over medium heat until no longer pink; drain. Stir in the taco seasoning; cool.
Drain pasta and rinse in cold water; stir into meat mixture.
Add the lettuce, tomatoes, cheese, onion, green pepper and dressing; toss to coat. Serve with zesty cheese tortilla chips on top of the salad ( some people crumble the chips right into the salad but they go soggy if you have leftovers ).