Microsoft on Monday opened its flagship store in Manhattan. With an area of more than 22,000 square feet, it’s the company’s largest store and its 113th brick-and-mortar retail establishment. It’s also the first Microsoft store that’s two stories high. The company gutted a 1930s building that was previously a Fendi store and replaced the street-facing facade with giant glass panes. The building has a 40- by 20-foot exterior culture wall that will display noncommercial artistic images.