Bill Gates co-founded Microsoft in 1975 and launched the company's first operating system, MS-DOS, in 1980. He introduced Windows 1.0 in the early 1980s, which helped propel Microsoft to success. By the 1990s, Microsoft had launched several new versions of Windows and had become the world's largest PC software company. Gates transformed technology and became the richest man in the world through his leadership of Microsoft and commitment to developing new operating systems over decades.