Bill Gates is an American business magnate, philanthropist, investor, computer programmer, and inventor who co-founded Microsoft, the world's largest personal computer software company. He served as Microsoft's CEO until 2000 and later as chairman until 2014. Gates grew up in Seattle in an upper-middle class family and met Paul Allen while in high school, leading them to co-found Microsoft in 1975. Microsoft developed the widely used Microsoft Windows operating system and Microsoft Office software suite. Gates stepped down as CEO in 2000 but remained chairman until 2014, taking on an advisory role to new CEO Satya Nadella.