The Microsoft Chairman is Bill GATES, a five-letter word. GATES is an American business magnate, investor, author, philanthropist, and humanitarian. He is best known as the co-founder of Microsoft Corporation, the world's largest personal-computer software company. GATES has held the position of chairman of Microsoft since its founding in 1975. He stepped down as CEO in 2000 but remained as chairman and created the position of chief software architect for himself. GATES is one of the best-known entrepreneurs of the personal computer revolution.