It’s not in the same league as McDonald’s Hamburgers (however many billion they’re up to by now), but it ain’t at all bad. Microsoft has sold more than 350 million copies of Windows 7 in the 18 months since its general availability (GA) date of October 22, 2009. That’s almost double what Vista sold 18 months out of the gate (180 million, according to Paul Thurrot’s recent Windows IT Pro article on this subject), and 50 million more than what the now-revered Windows XP sold when it had been out for 18 months (130 million, also according to Thurrot’s story).
This also means that Windows 7 has managed a run rate of nearly 20 million units per month (19.44 M to be more precise) since the product first shipped. A different basis for comparison in terms of percentage of PCs sold with Windows pre-installed over the same time period puts the numbers like this: 67 percent for Windows 7, 44 percent for Vista, and 54 percent for XP. Where some readers may be inclined to see this Windows 7 number as high, however, Thurrott is inclined to see it as low because he explains that it includes retail box sales or downloads for Windows 7 upgrades to existing PCs as well as for new PC sales with the OS pre-installed. Given that Windows 7 has sold lots of copies for upgrades, he’s guessing this puts the real new PC share closer to the XP number of 54 percent. Rightfully, he goes on to wonder why so many PCs are still selling with an older Windows OS installed, and guesses that makers are still selling lots of lower-powered PCs with XP installed, especially in less-developed markets outside the first world (shoot, Asus was selling netbooks with XP pre-installed until the end of 2010, and didn’t switch over to Windows 7 Starter edition until their OEM contract for XP ran out).
However you choose to slice and dice these numbers, I agree with Thurrot and others that Windows 7 is the best selling PC OS, ever. And with the end of the line for XP coming soon (no more licenses for sale as of October 22, 2010, one year after Windows 7 GA) and the life-cycle scheduled to end on April 14, 2014, I also agree with Thurrot that Windows 7 may still have its best sales in months and years ahead, before Windows 8 comes along some time in 2012 or thereabouts.