Overview
- Microsoft CEO Satya Nadella announced the milestone on the fiscal Q2 2026 earnings call, noting Windows 11 usage rose about 45% year over year.
- Windows 11 reached 1 billion in 1,576 days, compared with 1,706 days for Windows 10 to hit the same mark.
- Microsoft has not defined what the "1 billion users" figure represents, leaving unclear whether it counts devices, active users, or the user mix.
- Adoption was propelled by the October 2025 end of Windows 10 support and new PC shipments, though strict Windows 11 hardware requirements limited direct upgrades on older machines.
- Following recent buggy updates, Microsoft says it is redirecting engineers to improve Windows 11 performance, reliability, and the overall experience using a "swarming" approach.