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

UEFI

Unified Extensible Firmware Interface.

You can’t run Windows XP on UEFI without serious modifications.

by PhoneGuyYT June 08, 2025

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

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