Microsoft had plans for a custom operating system called Andromeda OS, designed for dual-screen devices, which was ultimately shelved. A leaked build of Andromeda OS has been ported to the original Surface Duo by developer Gustave Monce, allowing users to experience this unfinished software. Andromeda OS was based on Windows 10 and resembled Windows Phone, featuring Live Tiles and a Start Menu for dual displays. The project was abandoned in favor of Android in 2018 to avoid rebuilding a mobile app ecosystem. The ported build is not compatible with Surface Duo 2 and is available for download, but installation will erase existing Android data and may not be suitable for beginners. The device can run both Android and Windows, but booting into Windows requires a PC connection. The current version of Andromeda OS is unstable and incomplete, providing insight into Microsoft's previous mobile technology aspirations.