According to a post, an old Microsoft PolarisOS Build 16299 built for ARM-based devices was leaked online without a composer (shell) or software.
An early build of Polaris, a Windows Core OS cancelled SKU, has leaked online. The build is from early 2018, and contains nothing but the bare core OS, meaning there’s no composer (shell) or apps present. A new version of Windows that drives HoloLens 2 and the upcoming Windows 10X, Windows Core OS has been in use for several years.
Microsoft secretly worked on a customizable variant of the Windows platform called Windows Core OS for those who were unaware. With Windows Core OS, Microsoft wanted to sell various Windows flavors/SKUs for various form factors, such as tablets, 2-in-1s, dual-screen PCs, and collaboration devices.
Given below is the readme file from the leak:
“This is PolarisOS. It’s a cancelled edition of Windows Core OS that was designed for Desktops and Laptops. This image is early enough to not include much more than the OS itself. It comes with no shell, and won’t load any.
You need an ARM device to boot this, and you need to sideload drivers before first boot. The wim is bootable, but you can also install it directly by applying index 1.
To install on a phone instead of an arm tablet, go to catalog.update.microsoft.com, find the latest firmware for your phone, download all MainOS cabinets for it, place all of them in a folder, and run dism /Image: /Add-Package /PackagePath:
To install on an arm tablet, get the tablet drivers, and run dism /Image: /Add-Driver /Driver: /Recurse
Upon boot, pressing the power button will shutdown the device, connecting the device over USB will expose a diagnostic interface, which you can use to open a command prompt shell afterwards”
Thanks to the leakage of Build 16299, which would be the compilation for the RS3 branch manufacturers, we can now assert the presence of Polaris. Although that may sound fantastic, the leak doesn’t mean that we’re going to be able to test Polaris. A shell or applications are not included in this compilation, because it does not have a GUI.