Microsoft kicked off is Build 2018 conference today by announcing that there are now nearly 700 million active Windows 10 devices. That's up by almost 200 million from a year ago, when Microsoft said there were 500 million active devices, and up by nearly 100 million since November.

That's some pretty solid growth in just a year's time, but it falls short of where Microsoft wanted to be when it launched Windows 10 in 2015. At the time, Microsoft was aiming to have Windows 10 on one billion active devices within its first three years. Microsoft later reined in expectations, acknowledging in 2016 that it would not meet its goal.

Keep in mind that Microsoft counts Windows 10 PCs, tablets, Xbox, HoloLens, and Windows 10 mobile devices in that 700 million number. Still, it's nothing to scoff at.

In other numbers, Microsoft also revealed that Office 365 has 135 million monthly active commercial users. For a service that makes up a growing piece of Microsoft's portfolio, that's a solid base of users.