Sinofsky, 47, had been widely seen as Ballmer's likely successor. After joining the company as a software engineer in 1989, Sinofsky eventually became a technical adviser to Gates and later oversaw the Office package that includes word processing, spreadsheet and email programs. He took charge of Windows in 2006 and helped the company recover from the buggy Vista version of the operating system with the release of Windows 7 in 2009. More than 670 million licenses of Windows 7 have been sold since then.
Sinofsky "is a good manager and a guy known for getting things done, but if you are looking for someone who plays well with others, he is not your guy." Enderle said.
Ballmer praised Sinofsky in an upbeat email sent to company employees Monday.
"What we have accomplished over the past few years is nothing short of amazing, and I know we have more amazing in us," Ballmer wrote. "I am excited about our people, I am energized by our ability to change and grow, and I look forward to the success which lies ahead."
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