Even so, it's likely that XP will remain on PCs for years to come. Net Applications' newest data indicated that if Windows XP continues to lose share at the average pace of the last three months, it won't dip under 50% until July 2011, and will still account for a quarter of all OSes in early 2013.
Windows 7 has benefitted from XP's decline.
Microsoft's newest operating system added 1.5 points to its share last month, ending January at 22.1%. If its current adoption rate continues, Windows 7 should have a 40% share by this time next year.
Last week during a quarterly earnings call, Microsoft executives boasted that the company has sold more than 300 million Windows 7 licenses since the October 2009 launch. Revenues for the Windows division were nearly flat, as PC sales have slowed dramatically.
Vizzaccaro noted that while Windows PC sales have lost the momentum they had in 2009 and early 2010 -- when Windows 7's debut was driving purchases -- Apple has logged several record quarters of Mac, iPhone and iPad sales.
"The increase in Mac OS and iOS coincides with Apple's sales," said Vizzaccaro. And the growth of both show that fears of iPad and iPhone cannibalization of Mac desktops and laptops may be unfounded.
"Clearly, iOS and Mac OS can co-exist," said Vizzaccaro.
Net Applications' January operating system data is available on its site.
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