Gates's increasingly belligerent attitude was a major factor in the US and EU governments' anti-trust actions against Microsoft, Allen writes.
Allen said he told Gates that Internet Explorer did not need to be tied to the operating system, but Gates insisted on it to combat Netscape, and then made matters worse in hearings with the US Justice Department.
"Bill was sarcastic, combative, defensive and contemptuous," he writes. "I knew these traits well, but they were less than helpful on the stand."
Steve Ballmer, initially a divisive figure in the Allen/Gates relationship, is also praised for his drive. Ballmer forced Gates to expand the company earlier than he would have liked in order to meet the orders Ballmer's sales team were bringing in.
However, Allen is tepid about Ballmer's leadership. Vista was described as a debacle and Microsoft internally is slammed for having too many sub-par managers and poor process control.
"To avoid mediocrity, you need to be rigorous in weeding out underperformers," he said. "Microsoft hasn't proven to be good at that. One executive recently told me: 'I wish I could shoot every fourth one.'"
Allen also includes considerable self-criticism in the book. He describes, in painful detail, taking an $8bn loss in the cable industry, but is justifiably proud of his involvement in funding commercial space travel and some of his investment decisions.
Allen was an early investor in America Online and held nearly a quarter of the company at one point. But he said that chief executive Steve Case was wedded to the idea of AOL's ‘walled garden' strategy and was unwilling to accept the coming increase in broadband access.
Allen sold his stock for a $75m profit in 1994, but points out that it would have netted $40bn if he'd held onto it for another six years.
The book details Allen's other activities, including owning and developing two professional sports teams, his work funding artificial intelligence and information management research, and jamming with Mick Jagger and Peter Gabriel.
Allen concludes that progress relies on coming up with genuinely new ideas that are of their time, and seeing that there is a good team to carry them through.
While suffering from increasing health problems, he is looking forward to spending more time developing commercial space travel and other concepts.
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