The original Xbox BIOS was a remarkably robust piece of security for 2001, but its true "review" value lies in its . While the retail version is a historical relic that keeps the console locked, the custom BIOS community transformed the Xbox into the ultimate media centre and homebrew machine of its era.

: A classic choice used for its simplicity and broad compatibility across different console versions.

Introduced stricter checks on the hard drive. If the hard drive was locked with a different motherboard's unique HDD key, the BIOS would throw Error 07 (HDD timeout). This forced modders to use EEPROM readers.

As of 2024-2025, is the gold standard. It is a brand-new, ground-up custom BIOS built using the leaked source code. Features include:

The story of the Xbox BIOS is inextricably linked to the modchip era.