Raspberry Pi 4 warnings:
There is currently only one legal way of obtaining Windows 10 ARM64 images: download the UUP files directly from Microsoft servers, and build an ISO from them.
Full desktop builds of Windows 10 ARM32 are not available anywhere (except for a leak, but please read the warning below before going straight to Google).
You can get instead a version of the Windows Preinstallation Environment (WinPE) built for ARM32. A guide can be found here.
FFU images can speed up the deployment process significantly, especially on slow devices. They are not available for download due to legal reasons, but you can safely generate them yourself: How to generate FFU images?
Any other method of downloading images (such as prebuilt images, leaks, etc.) is not supported by us!