Before Microsoft shipped the Surface Duo with Android, it was meant to run a custom version of Windows called Andromeda OS, built specifically for dual-screen devices. That plan was quietly scrapped years ago.
Now, thanks to a leaked build and some serious developer effort, you can finally see what Microsoft was working on and even try it yourself.
For the uninitiated, Andromeda OS was a Windows 10-based platform that looked and felt a lot like Windows Phone, complete with Live Tiles and a Start Menu designed to stretch across two displays.
Microsoft originally envisioned it as the software foundation for early dual-screen hardware, including the first Surface Duo. But in 2018, the company shut the project down, pivoting instead to Android to avoid rebuilding a mobile app ecosystem from scratch.
How Andromeda OS made its way onto Surface Duo
As reported by Windows Central, the canceled software stayed hidden until a leaked, unfinished build surfaced online. Developer Gustave Monce took that build and successfully ported it to the original Surface Duo. He also mentioned that the port does not work on Surface Duo 2 due to missing driver support.
If you want to try it, you can download the Andromeda OS build as an FFU file and follow the flashing instructions shared on Monce’s GitHub. But consider this as a warning that the process will wipe your Android data, and the setup is not beginner-friendly.
After installation, the device can technically run both Android and Windows, sharing internal storage, though booting into Windows requires a PC. The version available is unstable and clearly incomplete, but it offers a rare glimpse into Microsoft’s abandoned mobile vision. It probably was Microsoft’s last serious attempt to rethink Windows on mobile, and now, for the first time, you can see what might have been.
In its current state, the build is unstable and unfinished, but it offers a rare glimpse into Microsoft’s abandoned mobile vision. Andromeda OS feels like the company’s last serious attempt to rethink Windows on phones, and a reminder of just how different the Surface Duo might have been.
For anyone wondering what a modern Windows Phone might look like, here are some mockup designs, showing how Microsoft’s mobile past and speculative designs continue to capture the imagination.