Microsoft on Sunday kicked off sales of Windows 7 Family Pack in the U.S., with most retailers selling the three-license package for the full list price of $150.
At the same time, new data from Web metrics company Net Applications showed that Windows 7's growth has slowed from the torrid pace of 2010's first quarter.
The Family Pack gives consumers three upgrade licenses from Windows XP or Vista to Windows 7 Home Premium. The $150 price tag is the same price that Microsoft put on the package last year when it offered the deal for several weeks after Windows 7's launch. As in 2009, Microsoft said it will offer the Family Pack for a limited time only, but has not set an end date for the deal.
Microsoft will re-launch Family Pack in another 45 countries on Oct. 22.
On Sunday, most U.S. retailers listed Windows 7 Family Pack at the full price of $149.99. Microsoft's own online store also posted that price.
Amazon.com was one of the few that didn't toe the line: The giant online seller listed Family Pack for $139.99 , a $10 discount.
At Amazon's price, the Family Pack saves buyers $190 compared to the price of three separate Windows 7 Home Premium upgrade licenses.
Consumers understood the bargain: By late Sunday, Windows 7 Family Pack was the No. 2 bestselling program in Amazon's software category, lagging behind only the $100 Office 2010 Home & Student application suite.
Windows 7 could use a bit of a boost, according to new statistics from Aliso Viejo, Calif.-based Net Applications.
In the quarter that ended Sept. 30, Windows 7 gained 3.4 percentage points of share, said Net Application, which measures operating system use by tracking machines that browse the Web.
The 3.4-point increase was slightly off the 3.5 percentage points that Windows 7 gained in the second quarter of 2010, but down a full percentage point, or 25%, from the stronger growth of 4.5 points in this year's first quarter.
Windows 7 gained 8.7 percentage points in its first two quarters of availability -- the final three months of 2009 and the first three of 2010 -- compared to a 6.9-point increase in its second two quarters.
As in months past, Windows 7's gains during September came at the expense of the older Windows XP and Windows Vista editions. While Windows 7 posted a 1.2-point percentage increase last month to put it at a 17.1% share of all operating systems, Windows XP dropped nearly nine-tenths of a percentage point and Vista fell by about seven-tenths of a point.
Windows XP remained the dominant operating system by a wide margin last month, accounting for a 60% usage share. Vista fell to 13.4%, its lowest mark since October 2008.
Both Microsoft and industry analysts have urged users of Windows XP to upgrade to Windows 7 as the nine-year-old operating system closes on its 2014 retirement. Later this month, Microsoft will require OEMs to stop preinstalling Windows XP Professional on new PCs using the downgrade rights built into Windows 7 Professional.
But Windows XP refuses to die: If the operating system's 12-month trend continues, XP won't drop under 50% until August 2011. By then, Windows 7 should hit the 31% mark and Vista will have fallen under 9%.
Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld. Follow Gregg on Twitter at @gkeizer or subscribe to Gregg's RSS feed . His e-mail address is email@example.com .
Read more about windows in Computerworld's Windows Topic Center.
This story, "Windows 7 Family Pack Discount Deal Returns Amid Cooling Sales" was originally published by Computerworld.