How does the bios of ASUS notebook close UEFI mode and replace it with Legacy mode?

The steps to change UEFI mode to traditional mode are as follows:

1. Press "ESC" continuously to enter the BIOS setup page, and the keyboard moves to the "Boot" tab. Change the Boot Mode to Legacy Support (UEFI by default), and then press Enter to confirm.

2. Change the "startup priority" to "Legacy First" (UEFI First by default), press the shortcut key F 10 to save, and then the computer will automatically restart. If the computer doesn't have this item, skip it directly and continue to the next step.

3. When starting the computer again, press "ESC" to enter the BIOS panel, enter the "Security" tab, select the security startup control, then press Enter to select disable in the drop-down menu, and press Enter again to confirm.

4. Then switch to "Boot", select Launch CSM, press enter, change to Enabled, save with F 10, and restart the system again, waiting for the system to restart.