Last summer, Microsoft announced that it had sold 175 million Windows 7 licenses through the end of June 2010. Cranking together a few numbers produced some surprising results, which I talked about in my July 26, 2010, article "Do the math: 175 million copies of Windows 7 isn't that impressive."
Last Friday, Brandon LeBlanc said the following on the Windows Team Blog: "18 months ago to this day was when we launched Windows 7 and with that we've hit another important milestone: we are pleased to announce that Windows 7 has sold more than 350 million licenses. The momentum we've seen and continue to see with Windows 7 is incredible."
Fair enough. Let's do the math once again.
Microsoft released Windows 7 on Oct. 22, 2009. On June 30, 2010, the company claimed it had sold 175 million copies. On April 22, 2011, Microsoft pegged the number at 350 million.
As I explained in my July 26 article, worldwide PC shipments between Oct. 22, 2009, and June 30, 2010, ran about 215 million machines, give or take a bit, based on Gartner's numbers. (IDC's numbers are just a touch lower.) Rifling through Gartner's press releases over the past year, I come up with a total of 266 million PCs and Macs sold between July 1, 2010, and March 30, 2011. Taking 9 percent off that total for Mac sales and adding a proportional amount to fill in the gap from April 1 to 21 of this year, I figure total worldwide PC sales between July 1, 2010, and April 21, 2011, came in around 260 million machines, give or take a few percent.
Here's where the numbers get strange -- very strange.
Between launch and June 30, 2010 -- a period of 251 days -- Microsoft sold 0.78 Windows 7 licenses for each PC sold.
Between July 1, 2010, and April 22, 2011 -- a period of 275 days -- Microsoft sold 0.67 Windows 7 licenses for each PC sold: 175 million Windows 7 licenses, and 260 million new PCs.
To turn the numbers the other way around, in the past nine months, more than one-third of all new PCs sold didn't have Windows 7.
How is that possible?
Microsoft doesn't release separate figures for single, shrinkwrapped copies of Windows 7 sold, nor does the company tell us how many volume licenses for Windows 7 are upgrades to existing machines. Each of those sales numbers would add to the percentage of new PCs shipped sans Windows 7. If the adoption rate for Windows 7 is as great as Microsoft would have us believe, it's entirely possible that 40 percent of all new PCs in the past nine months shipped without Windows 7. Maybe more.
Do the math.
This article, "Microsoft's own numbers suggest declining Windows market share," was originally published at InfoWorld.com. Get the first word on what the important tech news really means with the InfoWorld Tech Watch blog. For the latest business technology news, follow InfoWorld.com on Twitter.