Cook chicken until tender and cut into small pieces.
Prepare noodles according to package directions.
Combine chicken with sour cream, soup and noodles and add salt and pepper to taste.
Pour into 9 X 13 baking dish, cover and refrigerate overnight.
Before baking, crush the crackers and sprinkle over chicken mixture. Melt stick of butter and pour it over the crackers.
Bake uncovered at 350 degrees for 40 minutes.