Windows 11 is reportedly in use by more than 400 million monthly active devices. Windows Central reports that it has seen “Microsoft internal data” that shows Windows 11 is expected to hit 500 million monthly active devices by early 2024. All signs have pointed towards a slower adoption of Windows 11 than its predecessor and this leaked data backs up the assumption.

Windows 10 first reached 400 million active devices just over a year after release, an adoption rate that Microsoft proudly noted was 115 percent faster than Windows 7. It has taken Windows 11 two years to reach that same adoption rate, a significant slowdown considering Windows 10 reached 600 million devices a few months after its two-year anniversary.

Microsoft first launched Windows 11 in October 2021 with strict hardware requirements. Windows 11 is only supported on CPUs released from 2018 onwards, and with devices that support TPM security chips. Microsoft shifted the minimum system requirements in order to focus on raising the security threshold in Windows 11, with modern chips capable of enabling memory integrity security features that rely on virtualization and Microsoft’s Virtual Machine Platform (VMP).

These hardware requirements have meant that Windows 11 has lagged behind the Windows 10 rollout, which was also offered to Windows 7 and Windows 8 users as a free upgrade. Windows 11 was a free upgrade for Windows 10 users, but only if they met the minimum hardware requirements that left millions of machines behind.

We’ve seen the slow adoption reflected in Steam survey data, with Windows 11 only counting for 37 percent of operating systems, compared to nearly 60 percent for Windows 10. Statcounter puts Windows 11’s market share at nearly 25 percent, far behind the more than 70 precent of Windows 10.

Microsoft has never officially shared how many active devices are running Windows 11. The software maker used to offer a combination of Windows 10 and Windows 10 monthly active devices on its “Microsoft by the numbers” website, but that was quietly discontinued late last year. A cached page reveals there were more than 1.4 billion monthly active devices running Windows 10 or Windows 11 in April 2022, according to Microsoft.

Microsoft’s own support for Windows 10 is set to end on October 14th, 2025, meaning an end to security updates and fixes for millions of machines. If Microsoft isn’t able to convince more businesses and consumers to switch to Windows 11 (or whatever comes next) by 2025, then it seems likely that the company will need to extend that support cutoff date.

Microsoft hasn’t announced any plans for Windows 12, but there are signs a future version of Windows will be focused on AI. “As we start to develop future versions of Windows we’ll think about other places where AI should play a natural role in terms of the experience,” said Yusuf Mehdi, Microsoft’s head of consumer marketing, in an interview with The Verge earlier this year.