Microsoft released the final version of its next major update to Windows 11 (22H2) for Release Preview testers on Tuesday, accidentally making it available for computers that are not officially supported. Error.

Twitter and Reddit (Neowin) users noticed the error right away: hundreds of people inside Windows have managed to upgrade their Windows 10 machines to older processors. Microsoft has strict minimum hardware requirements for Windows 11 and leaves millions of PCs behind, so the bug will underline the company’s controversial upgrade policy.

Windows 11 officially requires Intel 8th Gen Coffee Lake or Zen 2 and higher processors with a few exceptions. While there are easy ways to install Windows 11 on unsupported processors, Microsoft does not even allow Windows insiders to officially install beta versions of the operating system on unsupported computers, so this flawed version is rather unusual.

Microsoft is aware of the bug and says it’s investigating. “This is a bug and the right team is investigating it,” said the official Windows Insider Twitter account. If you were able to install Windows 11 on an unsupported computer and are only waiting for a Release Preview update for Windows 10, you should be able to roll back an unexpected update in the Windows 11 settings section.