Beginning in January 2012, Microsoft started upgrading some PCs running Windows XP from IE6 or IE7 to IE8, and swapping IE9 for IE7 or IE8 on Vista and Windows 7.
That new practice would not explain the April increase in IE7, however.
Chrome was the only browser besides IE to post positive numbers for the month, growing by three-tenths of a percentage point to 18.9%. Mozilla's Firefox and Apple's Safari both lost share -- four-tenths and three-tenths of a point, respectively -- to end April at 20.2% and 4.8%.
The Norwegian browser Opera remained flat at 1.6%.
Chrome's recovery was notable because Google's browser has slipped each of the first three months of the year, the only multi-month decline ever for the 2008 program. Chrome's setback has effectively squashed projections that said it would surpass Firefox as the world's No. 2 browser this summer.
Firefox's decline, on the other hand, was standard fare for the open-source browser, which has jettisoned share eight of the last 12 months. Last month's number was Firefox's lowest since October 2008.
As usual, data from Irish metrics firm StatCounter sketched different results. Unlike its U.S. rival Net Applications, StatCounter does not adjust its global numbers to take into account problems quantifying browser use in countries like China, nor does it discard Chrome's pre-rendered pages, which some claim inflate the latter's numbers.
StatCounter had IE falling by seven-tenths of a point to 34.1%, while Chrome grew by a relatively robust four-tenths of a point to 31.2%. Firefox, said StatCounter, dropped to 24.1%, while Safari scratched out an increase to 7.1%.
Net Applications calculates browser usage share with data obtained from more than 160 million unique visitors who browse 40,000 Web sites that the company monitors. More browser share figures can be found on the company's site.
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 gkeizer@computerworld.com.
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