In a large bowl, combine the popcorn, pretzels and pecans. Drizzle with butter and toss; set aside.
In a microwave, melt white candy coating at 70% power for 1 minute; stir. Microwave at additional 10- to 20-second intervals, stirring until smooth. Drizzle over popcorn mixture; toss to coat. Spread on foil-lined baking sheets.
In a microwave, melt milk chocolate coating; stir until smooth. Drizzle over popcorn mixture. Let stand in a cool place until chocolate is set. Store in an airtight container. Yield: 17 cups.