Microsoft executive Yusuf Mehdi tweeted the news on Thursday, thanking customers for helping the company to achieve this goal.
Microsoft reached the 700 million mark in September 2018, showing that the operating system has grown substantially – despite problems with its October Update.
Windows 10 was released in 2015, and it was originally hoped that the operating system would be running on a billion devices within three years of being released.
However, a year later, Microsoft said this goal would not be met.
Microsoft will release its next update in April 2019, which will include a light theme, the separation of Cortana from the search feature, and an integrated Microsoft Office app.
The previous Windows update, which was released in October 2018, has been Microsoft's least successful one to date.