UEFI Class 1

Basically just a Legacy BIOS with some UEFI stuff.
UEFI Class 1 systems are rare as fuck! I want one right now!
by PhoneGuyYT June 20, 2025
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UEFI Class 2

UEFI with optional CSM (Compatibility Support Module).
If you want to boot Windows 7, Windows XP or DOS on UEFI Class 2 systems, you have to enable CSM and disable secure boot.
by PhoneGuyYT June 20, 2025
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UEFI

Unified Extensible Firmware Interface.
You can’t run Windows XP on UEFI without serious modifications.
by PhoneGuyYT June 08, 2025
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UEFI Class 3

UEFI without any form of CSM/Legacy stuff.
You can install Windows 7 to UEFI Class 3 systems, but you need serious modifications.
by PhoneGuyYT June 20, 2025
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