One of the most successful business partnerships in history was coming unraveled. It was early 2000, and Bill Gates had relinquished the chief executives job at Microsoft Corp. to Steve Ballmer; for the first time taking a back seat to his college pal and right-hand man of 20 years. Mr. Ballmer got the title. But Mr. Gates retained the power, triggering a yearlong struggle between the two men that until now has remained largely under wraps.
Things became so bitter that, on one occasion, Mr. Gates stormed out of a meeting in a huff after a shouting match in which Mr. Ballmer jumped to the defense of several colleagues, according to an individual present at the time. The conflict between the two men paralyzed business-strategy decisions that the company still wrestles with today.
The differences between the two men ended, Mr. Gates and other Microsoft executives say, when in 2001 Mr. Gates had an epiphany, recognizing he needed to accept his role as No. 2. "I had to change," Mr. Gates says.