Will Windows 7 boost Apple sales?

    By Philip Elmer-DeWitt

    Over the past decade, Mac shipments have grown with nearly every new Microsoft release

    As if Steve Ballmer didn't have enough to worry about after last week's Sidekick/Microsoft (MSFT) Danger debacle, here's a bar graph that may add to his miseries.

    The graphic comes out of a report to clients issued Monday by Broadpoint AmTech analyst Brian Marshall. Anticipating the release of Windows 7 next week (Oct. 22), Marshall reviewed Mac sales figures over the past 10 years to analyze the impact of the four previous Windows launches:

    • Windows 98 (launched on June 25, 1998)

    • Windows 2000 (launched on February 17, 2000)

    • Windows XP (launched on October 25, 2001)

    • Windows Vista (launched on January 30, 2007)

    His findings:

    "We have concluded that no negative correlation exists on Apple's (AAPL) hardware sales when Microsoft launches a new OS. Ironically, we believe new OS launches from MSFT may have even acted as a 'delayed accelerant' to AAPL's computing sales."

    The chart suggests that Vista's well-publicized problems were the real accelerant, providing fodder for more than two years of Get A Mac ads.

    Correlation is not causation, of course, and Marshall is quick to add that "AAPL's success (or failure) in the computing market is largely idiosyncratic (or company-specific) in nature and not dependent on others in the industry."

    Still, he thinks that despite Windows 7 — if not because of it — Apple could double its global PC market share from about 4% today to 8% over the next five years.