Google's Chrome's share also climbed in April, said Net Applications, ending that browser's .
IE boosted its share by about three-tenths of a percentage point last month to average 54.1% in April. That returns IE to a mark comparable to its September 2011 share.
Since Jan.1, IE has increased its usage share by 2.2 percentage points for a 4% gain since the end of 2011. The turnaround has been IE's largest and longest since the browser began shedding share years ago to Firefox, then later, Chrome.
Microsoft has pinned its hopes almost entirely on IE9, the 2011 edition that runs only on Windows Vista and Windows 7.
On Tuesday, Microsoft again stayed on message, highlighting the -- the pairing the firm has said is the only metric it cares about -- but ignoring the overall IE increases this year.
IE9 accounted for 35.5% of the world's browsers used on Windows 7 last month, an increase of one percentage point from March, said Microsoft, and owned a 52.9% share of the Windows 7 browser market in the U.S., a jump of four points. Both increases were significantly smaller than those claimed last month over February's numbers.
The browser's global share on all operating systems, however, is much lower, and for April stood at 15.9%, a bump of seven-tenths of a point.
Other versions of IE reported mixed results.
IE8, the last in the line for Windows XP users, gained eight-tenths of a point to scramble back to 26.2%, while IE7 unaccountably grew by two-tenths of a point to 7.1%.
IE6, the browser that Microsoft has been trying to put in the grave for years, lost three-tenths of a percentage point, closing April with 4.1%.
The shifts within IE's editions may have been partly due to Microsoft's new philosophy of . Late last year, the company said it would begin silently forcing Windows to upgrade IE to the newest-possible edition, ending its earlier practice of asking users' permission before making such a move.
Internet Explorer has been on a multiple-month rebound after hitting an all-time low last December. (Data: Net Applications.)
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. 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 , on or subscribe to . His email address is .
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