Preheat oven to 375°F. Combine frozen hash browns, cream of chicken soup, garlic salt, and half of cheddar cheese.
Spray 8x10 baking pan with non-stick spray. Pour potato mixture into pan. Spread evenly and sprinkle the rest of cheddar cheese all over top. Sprinkle crunched up corn flakes evenly over entire casserole (until cheese is covered). Evenly pour melted butter over top of cereal (browning purposes).