If you Like my video plz SUBSCRIBE: How to enable Legacy Support in bios to Install Windows from Bootable Usb Drive. The -legacy basically tells bless that the Operating System that is going to boot doesn't support OpenEFI or EFI and expects a BIOS instead. Bear in mind that you might need to later use fdisk to set the active partition if ubuntu fails to boot. To create a bootable USB that supports both Legacy and UEFI Boot options proceed as follows. Open Rufus utility. Select the USB drive onto which you want to create the live bootable media. In order to support both UEFI and Legacy boot select the first option i.e MBR Partition scheme for BIOS and UEFI under partition scheme and target system type.
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
- Install AIO Boot to a partition on GPT disks.
- 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.
- Run AIOCreator.exe, select Grub2 from Bootloaders. The tool will list the partitions that you created in step 2.
- 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.
- Install AIO Boot to a partition on GPT disks.
- Run AIOCreator.exe.
- 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.
- Please note that you should reinstall Grub2 every time you defragment on this drive.
Good luck!
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Choose UEFI or legacy BIOS modes when booting into Windows PE (WinPE) or Windows Setup. After Windows is installed, if you need to switch firmware modes, you may be able to use the MBR2GPT tool.
In general, install Windows using the newer UEFI mode, as it includes more security features than the legacy BIOS mode. If you're booting from a network that only supports BIOS, you'll need to boot to legacy BIOS mode.
After Windows is installed, the device boots automatically using the same mode it was installed with.
To boot to UEFI or BIOS:
Open the firmware menus. You can use any of these methods:
Boot the PC, and press the manufacturer’s key to open the menus. Common keys used: Esc, Delete, F1, F2, F10, F11, or F12. On tablets, common buttons are Volume up or Volume down (find more common keys and buttons). During startup, there’s often a screen that mentions the key. If there’s not one, or if the screen goes by too fast to see it, check your manufacturer’s site.
Or, if Windows is already installed, from either the Sign on screen or the Start menu, select Power () > hold Shift while selecting Restart. Select Troubleshoot > Advanced options > UEFI Firmware settings.
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 Drive. Each command uses the same device and media, but boots the PC in a different firmware mode.
Some devices only support one mode (either UEFI or BIOS). Other devices will only allow you to boot to BIOS mode by manually disabling the UEFI security features. To disable the security features, go to Security > Secure Boot and disable the feature.
Note
Some older PCs (Windows 7-era or earlier) support UEFI, but require you to browse to the boot file. From the firmware menus, look for the option: 'Boot from file', then browse to EFIBOOTBOOTX64.EFI on Windows PE or Windows Setup media.
UEFI and BIOS modes in WinPE
Detect if WinPE is booted into BIOS or UEFI Mode
Query the registry to determine which mode the device is in. You can do this from the command line:
| Return code | Firmware mode |
|---|---|
| 0x1 | BIOS |
| 0x2 | UEFI |
Bless A Usb For Legacy Boot Free
Use it in a script:
Note that between delims= and ' %%A is a tab, followed by a space.
Make sure you boot into the right mode every time
Here are a couple of ways you can make sure you're booted into the right firmware mode every time you start your PC.
Use preformatted hard drives, and use a method that doesn't automatically format the drive.
Bless A Usb For Legacy Boot
If you want to ensure that your drive boots into a certain mode, use drives that you've preformatted with the GPT file format for UEFI mode, or the MBR file format for BIOS mode. When the installation starts, if the PC is booted to the wrong mode, Windows installation will fail. To fix this, restart the PC in the correct firmware mode.
Remove the UEFI or BIOS boot files
If you want a PC to only boot into a certain mode, you can remove the files that Windows PE or Windows Setup use to boot in UEFI or BIOS mode. Remove the following files, depending on the mode you want to boot to.
Boot only when in UEFI mode
Remove the bootmgr file from the root of the Windows PE or Windows Setup media. This prevents the device from starting in BIOS mode.
Boot only when in BIOS mode
Remove the efi folder from the root of the Windows PE or Windows Setup media. This prevents the device from starting in UEFI mode.