A standard .iso file won’t boot on an original Xbox. Xbox discs use a (Xbox File System / XDVDFS) with:
(often referred to as version 1.3.1.17 in documentation) is an essential, open-source utility for managing Xbox disc images, specifically designed to handle the XDVDFS (Xbox DVD Filesystem) format. Key Features & Capabilities xbox xiso manager 131 377 upd