Since this is a legacy preview build from 2015, official direct download links from Microsoft are no longer active. Enthusiasts and historians can typically find verified ISO files through archival sites:

A: There is none. Microsoft purged all pre-release ISOs from their servers after the RTM launch. You must rely on community archives.

Build 10074 may overwrite your UEFI firmware settings or cause driver conflicts on modern hardware (NVMe drives, Wi-Fi 6 adapters). Only attempt on legacy hardware (Intel 4th gen or older).