Place chicken into bottom of slow cooker. Sprinkle with dressing mix; pour in soup.
Cover, and cook on low 6-7 hours.
Shred chicken, and return to crock. Add cream cheese and sour cream. Cover, and cook on low another 15 minutes or until cream cheese softens.
Meanwhile, cook pasta according to package directions.
Drain, and add to slow cooker; stir to combine.