> For the complete documentation index, see [llms.txt](https://cheesehubvip.gitbook.io/penguinby-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cheesehubvip.gitbook.io/penguinby-docs/wardogs/unsupported-firmware..md).

# Unsupported firmware.

Solution: To fix this error, convert the disk containing the operating system to GPT format using the mbr2gpt tool built into Windows or any other disk management utility of your choice. The BIOS needs to switch from Legacy mode to UEFI mode.