You cannot legally download an Xbox BIOS from the internet. The Long Answer: The Xbox BIOS is copyrighted software owned by Microsoft. Distributing it is piracy. However, backing up your own console’s BIOS for personal use generally falls under fair use in many jurisdictions.
To set up the emulator, you must provide specific system files that represent the original Xbox hardware. Because these files are copyrighted, they are not bundled with the software and must be sourced from your own hardware or through community-vetted archives. Required System Files Xbox Bios Files For Xemu
Once you have your BIOS file (commonly named mcpx_1.0.bin for the boot ROM and a secondary system BIOS like complex_4627.bin ), follow these steps: Open and navigate to Settings > Machine . You cannot legally download an Xbox BIOS from the internet