Bring a large pot of lightly salted water to a boil. Add fettuccine and cook for 8 to 10 minutes or until al dente; drain.

Meanwhile, heat butter in a large skillet and brown chicken and mushrooms until chicken is cooked through. Season with garlic salt and pepper. Add whipping cream and cook until thick, stirring constantly. Add Parmesan cheese when at desired consistency. Serve over noodles.