Microsoft never published an official ISO or FFU (Full Flash Update) image for Build 15035. The build leaked via beta collectors and was shared as raw, unpacked system files (a "payload"). You cannot flash raw files to a phone.
This is not a daily driver. Build 15035 is a fossil. windows 10 build 15035 media builder
You cannot flash a beta build on a standard locked phone. Microsoft never published an official ISO or FFU
Windows 10 Build 15035 is unreleased, leaked software. Distributing the Media Builder tool (which contains no Microsoft code) is legal. However, downloading the actual 15035 system payload is a violation of Microsoft's copyright. You should only do this if you are a registered Windows Insider (though Microsoft no longer provides this build) or for academic/archival purposes. Key folders/files:
This is the headline act. The Media Builder could take the x86 (32-bit) version of build 15035 and, using a proprietary repackaging routine, reconstruct it into a bootable ARM32 image. This wasn't emulation—it was native execution. Suddenly, the build could run on early Qualcomm Snapdragon 835 laptops (like the HP Envy x3) and, more famously, on the Windows RT 8.1 Surface RT and Surface 2.
Microsoft had long abandoned ARM support for full Windows. The Media Builder resurrected it.