As Windows XP continued its decline, users who deserted the obsolete operating system shifted to Windows 7, not the newer Windows 8, more circumstantial evidence that commercial customers, not consumers, now drive PC sales.
Data from analytics vendor Net Applications showed Windows XP dropped one percentage point in user share last month, ending May with 25.3% of all desktop and notebook systems. It was the third consecutive month that XP shed one or more points of user share.
Most of May's lost XP share showed up on Windows 7, which gained eight-tenths of a point to reach 50.1%, the first time the 2009 OS has reached that milestone. Meanwhile, Windows 8 grew four-tenths of a percentage point, ending with a user share of 12.6%.
For the first time, Windows 8.1 accounted for more than half of the combined user share of it and the original Windows 8.
The rise of Windows 7 had been predicted by researchers who have noted a temporary boom in personal computer shipments to businesses as they rushed to throw XP on the ash heap. IDC, for example, has said commercial sales of PCs have climbed by double digits this year compared to last, but that consumers sales have sunk by similar rates.
Net Applications' statistics can be interpreted as proof of those trends, with Windows 7 -- the standard corporate OS now that XP has waned -- on the upswing at double the rate of Windows 8/8.1 because of the continued slump in consumer PC purchases. Most consumer-grade personal computers are now equipped with Windows 8.1.
In two of the last three months, Windows 7's gains have outpaced those of Windows 8.
The latter also continued to flirt with comparisons to Windows Vista, the 2007 Microsoft failure: At the 19-month mark, Windows 8 was barely ahead of Vista's share of all PCs running Windows.
Unless consumer PC sales pick up in a big way later this year, as some forecast or at least hope, or Windows 8 becomes acceptable to businesses, which virtually no one believes is in the short-term cards, Windows 7 will continue to gain ground as all traces of XP are slowly scrubbed from enterprises, a process that will take much of 2014 in the U.S. and longer elsewhere.
The dominance of Windows 7 -- and its apparent resistance to replacement by Windows 8 -- will probably mean a repeat in five years of XP's grudging retirement and a similar scramble near the end of Windows 7's support to find an alternative. Microsoft has promised to support Windows 7 until mid-January 2020. Assuming it continues to unveil a new operating system -- as opposed to interim updates like Windows 8.1 -- every three years, Microsoft will get two more shots to come up with a suitable substitute for Windows 7.
Net Applications calculates operating system user share -- an estimate of the fraction of the world's personal computers that run a specific OS -- by tallying unique visitors to the websites of its analytics clients.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer, on Google+ or subscribe to Gregg's RSS feed. His email address is firstname.lastname@example.org.
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This story, "Windows 7 powers more than half of all PCs" was originally published by Computerworld.