Sinofsky, a 23-year veteran of Microsoft, launched Windows 7 on time in 2009, a coup for the company after the debacle of Windows Vista, which had been delayed several times and was faced with problems even after it launched. Vista was one of Microsoft's few Windows failures, never acquiring more than a 20% share of the OS market.

According to Web analytics company Net Applications, Windows 8 has been adopted by relatively few users during its preview period. In July, the new operating system accounted for only 0.2% of all copies of Windows used that month.

In July 2009, Windows 7 -- which was about at the same stage as Windows 8 is today -- powered 1% of all Windows PCs, or five times the percentage of this year's upgrade.

Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at , on or subscribe to . His email address is .

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