Gerstner was chairman and CEO of IBM from April 1993 until February 2002. He is credited for restoring IBM to its former glory. Gerstner grew the Lotus customer base from 2 million users to over 22 million users. In 1994, he co-authored a book titled "Reinventing Education: Entrepreneurship in America's Public Schools". In 2001, Queen Elizabeth II awarded Gerstner the rank and title of Knight Commander of the British Empire (KBE) for his service to education and his contributions to the Internet.