Microsoft hasn’t said much about the Windows RT update that’s coming in September, but a new report says users should prepare for disappointment.

Unnamed sources told WinBeta that “Update 3” will include a pop-up Start menu, though it’s based on a version from the early days of the Windows 10 Technical Preview. While some users actually prefer the older version, it doesn’t support certain features such as resizing, drag-and-drop for programs, and Jump Lists. Apparently Microsoft couldn’t recreate this menu in Windows RT due to its use of XAML and several Windows 10 APIs.

WinBeta’s sources also claim that the Windows RT update won’t allow Windows Store apps to run in windowed mode on the desktop, nor will it support Continuum, which automatically switches between tablet and desktop interfaces when the user plugs in a keyboard. Again, the features rely on Windows 10 APIs and code that won’t run on Windows RT. (Users may be able to manually toggle between the Start screen and pop-up Start menu with a software button, at least.)

Officially, Microsoft has said that Update 3 will arrive in September, and that it’ll have "some of the functionality of Windows 10.” The whole ordeal is reminiscent of Windows Phone 7.8, a minor update meant to placate Windows Phone 7 users after Microsoft left them behind with Windows Phone 8.

Microsoft originally saw Windows RT as a way to bring its operating system to tablets with ARM-based architecture, the same found on Apple’s iPad and most Android tablets. But the software was severely limited by its inability to install desktop applications, and hardware vendors quickly abandoned it as better Intel tablet processors became available. Microsoft stopped carrying its own Surface 2 tablet after stock ran out in January, and the Surface 3 switched to Intel inside.

Why this matters: Given that Windows RT is a dead platform walking, it wouldn’t be surprising if Microsoft wasn’t moving mountains to bring the best Windows 10 features over. Still, the lack of Continuum and windowed apps would be disappointing for devices like the Surface RT and Surface 2, which Microsoft once pitched as the ultimate cross between a tablet and a laptop.