Windows 10 was publicly released 5 months ago and the number will likely climb a bit faster in the coming months as Microsoft is getting more pushy with its free Windows 10 upgrade offer. Do keep in mind that the 200 million figure includes all Windows 10 devices, and not just PCs.
So with 2015 at a close, Microsoft has 200 million installations in the bag. 200 million thanks to people upgrading for free, Windows Insiders testing new builds, and holiday buyers purchasing new PCs and tablets for their loved ones. Still, the company is a fair way away from their goal of 1 billion devices in three years, but I’m pretty hopeful that they will reach their goal.