System requirements for differential installation of uefi and legacy

Uefi → guid (gpt) needs to partition guid, support hard drives above 2TB, and set up uefi boot for uefi bios.

(guid (gpt) partition produces esp and msr partition) does not support 32-bit WIN7 and previous system versions of WIN7, supports 64-bit all systems, and supports 32-bit WIN8 and WIN10.

Legaug → mbr traditional bios boot does not support hard drives above 2TB.

The following points should be paid attention to when setting legacy startup from uefi bios to legacy bios:

1 disable safe startup (secure boot control off)

2 turn on CSM concurrent operation mode (launch SCM open)

3 system default off (OS optimized defaults off)

4 the system is set to CSM concurrent operation mode (CSM OS opens os mode selection)

5 change enable to legacy (boot mode legacy on)

6 turn off quick start in advanced options (fast bios mode off)

After setting up the BIOS, convert the partition table, change the gtp to mbr, and you can install the system normally.