An official, public Windows 8.1 ARM64 ISO does not exist. While Windows 8.1 was available for ARM-based devices, it was released exclusively as Windows RT 8.1, which was only pre-installed on specific hardware (like the Surface RT or Surface 2) and never sold or distributed as a standalone ISO for general installation. Key Limitations of Windows 8.1 on ARM
Since there is no "retail" ARM ISO, users often have to use tools like windows 81 arm64 iso install
No Official ISO: Microsoft did not provide a standalone ISO for Windows RT 8.1. It was exclusively an OEM (Original Equipment Manufacturer) license pre-installed on devices. An official, public Windows 8
Driver Scarcity: Because hardware vendors in 2013 were not targeting ARM64 for Windows, finding compatible drivers for GPUs, Wi-Fi chips, or touchscreens is the primary barrier to a functional system. Why Enthusiasts Still Try It was exclusively an OEM (Original Equipment Manufacturer)
Official Downloads: Microsoft provides Windows 11 ARM64 ISOs or VHDX files through the Windows Insider Program.