Microsoft today announced that its Windows 10 operating system has now been installed on more than 300 million devices. That’s up from the “more than 270 million devices” milestone announced on March 30.

“We’re seeing people at home, at schools, at small businesses, at large companies, and other organizations adopt Windows 10 faster than ever, and use Windows 10 more than ever before,” Yusuf Mehdi, corporate vice president of Microsoft’s Windows and Devices Group, wrote in a blog post.

Windows 10 was installed on over 75 million PCs in its first four weeks, passed 110 million devices after 10 weeks, 200 million in under six months, 270 million after eight months, and now 300 million after nine months.

Microsoft’s stated goal is to hit 1 billion devices in two to three years. So it’s getting there.

Microsoft today is also instructing people to upgrade if they haven’t already, because the date when doing so will no longer be free is fast approaching.

It will cost $119 to upgrade to Windows 10 Home after the July 29 one-year anniversary of Windows 10’s release, Mehdi wrote.

This version of Windows is different from previous versions because Microsoft is regularly rolling out new builds with new features and bug fixes. This is why Microsoft calls Windows 10 a “service.” And Microsoft is hoping to make that service more than three times as popular as it is now.