Targetfox97

@Jack37 Also, if you took a boot drive from some other.non-NUC' system, and are going to boot it on your NUC, even in legacy mode, you are carrying a lot of baggage, and hoping the system will work flawlessly. Even using a driver from some other NUC is not without the possibility of problems. From the firmware menus, boot to drive or network while in UEFI or BIOS mode: On the boot device menu, select the command that identifies both the firmware mode and the device. For example, select UEFI: USB Drive or BIOS: Network/LAN. You might see separate commands for the same device. For example, you might see UEFI USB Drive and BIOS USB. How To Enable Legacy Mode:1. When the Startup Menu displays, press F10 to open the BIOS Setup. Use the right arrow key to choose the System Configuration. Below are two examples of instructions I was given a couple of years ago for creating a bootable Windows 10 USB flash drive in order to be able to clean install Windows 10 on a UEFI boot only PC (not Legacy Boot mode). To create bootable UEFI USB flash drive for installing Windows 10 with UEFI 1. Format a USB flash drive to FAT32 file system.

1. Bless A Usb For Legacy Booth
2. Bless A Usb For Legacy Booth

GPT is modern and has many advantages over MBR. However, there are also some issues with GPT booting in Legacy BIOS mode. GPT is part of the EFI specification, of course it will work best in UEFI mode. But maybe it will not be compatible and can not boot up on the BIOS computer, see more here. Microsoft also does not support booting Windows on a GPT hard disk in Legacy BIOS mode. However, in some ways, you can still install Windows on a GPT hard drive even if your computer only supports Legacy BIOS mode.

So far, MBR is still supported in both UEFI and Legacy BIOS boot. However, there are several reasons that you must use GPT instead of MBR. You can only create partitions up to 2TB on MBR disks, if you need to create partitions larger than 2TB or the total size of partitions on disks larger than 4TB, use GPT instead of MBR. For 3TB and 4TB hard drives, you can create multiple partitions with full disk space without having to convert the MBR to GPT, see how to partition a 4TB hard drive.

AIO Boot now supports installing Grub2 on GPT disks including both HDD and USB. After installing Grub2, you can boot the GPT disk in Legacy BIOS mode.

Windows Boot Manager does not support booting into Legacy BIOS mode on GPT disks. AIO Boot uses wimboot to do this.

Install Grub2 with the boot partition

Bless A Usb For Legacy Booth

1. Install AIO Boot to a partition on GPT disks.
2. The grub-install, grub-bios-setup command on Linux and the grub-install.exe, grub-bios-setup.exe program on Windows require a boot partition on the GPT disk to install Grub2 for the Legacy BIOS mode. On Linux, this partition will be flagged as bios_grub. We will create a small partition of 1 to 10MB. You do not need to format and do not need to mount the drive letter for this partition. For USB, you can use the MiniTool Partition Wizard to create a second partition.
3. Run AIOCreator.exe, select Grub2 from Bootloaders. The tool will list the partitions that you created in step 2.
4. Select the partition and click OK to install Grub2.

Install Grub2 without a boot partition

This is a new feature of AIO Boot v0.9.8.1. It supports installing Grub2 on the GPT hard disk to boot in Legacy BIOS mode without creating a boot partition.

1. Install AIO Boot to a partition on GPT disks.
2. Run AIOCreator.exe.
3. Select Install Grub2 (Legacy) from the Tools button. This button only appears when the current hard disk is GPT and the current drive format is FAT32 or NTFS.
   
4. Please note that you should reinstall Grub2 every time you defragment on this drive.

Bless A Usb For Legacy Booth

Good luck!