Windows – Can’t find option to activate legacy boot mode on Asus EFI BIOS

uefiwindows 10windows 7

I installed Windows 10 on a PC but it has some incompatibilities with the graphic card. Now I want to install Windows 7, so I burned the ISO on an USB stick, and then I tried to boot the system with it. Instead of launching Windows 7 installer, the computer is booting directly to Windows 10.

I read some stuff over the internet that for Windows 7 installer to be bootable, I need to set the BIOS to legacy mode. However, on ASUS EFI BIOS version 2.00.1201, I can't find this option anywhere. I selected the Boot tab and all I have is this:

Bootup NumLock State

Full Screen Logo

Wait For 'F1' If Error

Option ROM Messages

Setup Mode

Boot Option Priorities

Boot Option #1

Boot Option #2

> Hard Drive BBS Priorities

Boot Override

> SAMSUMG HD

> Windows Boot Manager

Now, where is the option of setting boot mode to legacy?

Best Answer

In some ASUS firmwares (e.g. "Aptio"), there is no such global choice – all available boot options are merged into a single menu (press Esc to open the boot menu one-time).

BIOS-mode boot entries always describe a specific disk rather than a specific OS (since they only boot the MBR 'bootcode' and don't know the OS name, unlike UEFI-mode boot entries which do). Of course, it's not impossible that an UEFI boot entry would be named after a disk, but that's rather unlikely...

For removable media, UEFI-mode entries also have an UEFI: prefix, while BIOS-mode entries either don't (as in your case) or are prefixed with BIOS: (on some other computers).

Therefore your options are:

  • SAMSUMG HD – BIOS
  • Windows Boot Manager – UEFI (stored in NVRAM)
  • General USB Flash Disk – BIOS
  • UEFI: General USB Flash Disk – UEFI (autodetected from removable drive)
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