As for how many of those licenses represent PCs that are actually being used, it's hard to say. The 100 million includes upgrades as well as PC sales. However, the vast majority of the 40 million licenses sold since January are new PCs, says Tami Reller, Microsoft's vice president of Windows marketing.
"Upgrade season was pretty much over in January once all the offers expired," Reller told Mashable. "So pretty much all of the growth from 60 to 100 [million] is new PCs."
However, those are PCs shipped, not necessarily sold, so many of them could still be in warehouses or store shelves. Windows 8, however, for the first time lets Microsoft directly track activations online, and Reller says those numbers have seen "steady" growth, and that the overall rate is similar to past Windows releases.
A new platform such as Windows 8 is only as powerful as the apps it has to offer, and the Windows Store is seeing steady growth as well, up to 60,000 apps from 40,000 in January. Customers have performed more than 250 million downloads as well. While the numbers are moving in the right direction for Microsoft, they're still in the minor leagues when you compare to iOS's 800,000 apps and almost 50 billion downloads.
Still, Microsoft has had some high-profile "gets" such as Twitter and Dropbox, which Reller thinks have attracted some users to Windows 8. But there are some notable absences in the Windows 8 app catalog as well, not the least of which is Facebook, a Microsoft strategic partner. Is a Facebook app coming?