By default, Windows RT only runs apps from the Windows Store (now largely defunct for RT) and Microsoft-signed software like Office 2013.
While using a patched ISO can breathe new life into an old tablet, it comes with significant caveats: windows rt 81 iso patched
Disclaimer: Modifying your operating system voids any remaining warranty and may violate software licensing agreements. The author is not responsible for bricked devices or data loss. Proceed at your own risk. By default, Windows RT only runs apps from