Microsoft has once again accidentally offered the Windows 11 upgrade to PCs with unsupported hardware. Twitter user PhantomOcean3 spotted the mistake earlier this week, where Microsoft was showing fullscreen prompts on unsupported hardware. Microsoft has now explained the mistake, noting that PCs that didn’t meet the minimum requirements for Windows 11 weren’t able to complete the upgrade.

“Some hardware ineligible Windows 10 and Windows 11, version 21H2 devices were offered an inaccurate upgrade to Windows 11,” explains Microsoft in a support note. “These ineligible devices did not meet the minimum requirements to run Windows 11. Devices that experienced this issue were not able to complete the upgrade installation process.”

Microsoft had a similar issue last year when it offered the Windows 11 upgrade to PCs that weren’t officially supported. That accident actually allowed those unsupported PCs to upgrade, but it did once again highlight the controversial strict minimum hardware requirements for Microsoft’s latest operating system.

This latest mistake comes just weeks before Microsoft is expected to deliver some additional improvements to Windows 11. In an update referred to internally at Microsoft as “Moment 2,” Microsoft is preparing to add a full search box to the taskbar, improve search in the Start menu, add a tablet-optimized taskbar, and roll out a redesigned system tray.