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Restore EUFI to MBR

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Regular Poster
Posts: 66
Comments: 149

I have computer A which is EUFI and computer B that is MBR. I want to be able to use a copy of the A disk on the B computer. I know I could change my BIOS on B to EUFI but since I change disks on B now and then (and all of my old disks are MBR), I'm wondering if I could restore an EUFI to an MBR by using Acronis in some way. Perhaps by first backing up A then format a disk as MBR then restoring all of A's disk without disturbing the MBR particulars.

Can anyone think of a way?

 

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Legend
Posts: 109
Comments: 28191

Eddy, you cannot use ATI to do this type of conversion without the disk becoming unbootable as far as I understand.

See webpage: How to Convert GPT Disk to MBR Disk?

Forum Hero
Posts: 70
Comments: 8346

I don't know of any backup / restore programs that can convert UEFI back to Legacy and remain bootable.... only legacy moving forward to UEFI - and REMAIN BOOTABLE. 

Acronis can go from legacy to UEFI and keep the OS bootable, but not the other way around.  Other backup tools usually have the same limitations.  Other tools, like partitioning software, will allow you to convert a disk from MBR to GPT and/or GPT back to MBR, but without the ability to remain bootable.  

How you boot the rescue media makes the difference on the outcome of the disk type.  Booting rescue media in legacy mode results in a legacy MBR disk and booting rescue media in UEFI mode results in a UEFI GPT disk.  This makes the difference when wanting to convert from MBR/Legacy to GPT/UEFI when restoring with Acronis. 

FYI, this is not unique to Acronis either.  This is the same behavior as Windows installer discs too.  How you boot your Windows installer determines how the OS will be installed.  Also, if your disk is MBR and you boot a Windows installer in UEFI mode, it will not allow you to install the OS because the disk must first be formatted as GPT.  If your disk is GPT and you boot a Windows installer in Legacy mode, it will not allow you to install the OS because the disk must first be formatted as MBR.  

Acronis does not have the limitation of not allowing you to proceed - it will restore the image regardless, but will restore it based on how the rescue media was booted. 

- If you have a Legacy/MBR OS backup and boot the rescue media in Legacy mode, it will restore in Legacy/MBR mode and be bootable (as long as the bios firmware supports it and is configured correctly).

- If you have a Legacy/MBR OS backup and boot the rescue media in UEFI mode, it will restore in UEFI/GPT mode and be bootable (as long as the bios firmware supports it and is configured correctly).

- If you have a UEFI/GPT OS backup and boot the rescue media in UEFI mode it will restore in UEFI/GPT mode and be bootable (as long as the bios firmware supports it and is configured correctly).  

If you have a UEFI OS backup and boot the rescue media in  Legacy mode, it will restore in Legacy/MBR mode and will NOT BE BOOTABLE.

 

 

Regular Poster
Posts: 66
Comments: 149

Bobbo_3C0X1 : There is a program that does it but it is not free: it is easeUS.

When I boot the rescue CD I don't see an option to boot in UEFI or Legacy. So how do I make that selection?

 

Legend
Posts: 109
Comments: 28191

KB 59877: Acronis True Image: how to distinguish between UEFI and Legacy BIOS boot modes of Acronis Bootable Media

From the ATI 2019 User Guide: Migration method

UEFI-booted system, MBR, UEFI supported

In this step of the wizard, you need to select the destination hard disk.

Currently your system contains:

System: UEFI-booted

Source partition style: MBR

Operating system on the source disk: Windows, booting in UEFI is supported

If you migrate the system to the selected disk:

After migration, the destination partition style will be converted to GPT and you will be able to boot from it.

Destination disk after migration:

System: UEFI-booted

Partition style: GPT

Operating system: Windows, booting in UEFI is supported

Disk size: the entire disk space is available

 

You can find more information about the migration procedure in Migration method section.

Forum Hero
Posts: 207
Comments: 4935

if the PC supports both legacy and UEFI it should have two choices for recovery media (USB stick or DVD). Older systems that do not support UEFI will not give you such a choice. This happens when you press the F11 key (or whatever key takes you to boot selection menu). It is possible that this may not happen if you change the first boot device; you would select UEFI or legacy when making that selection; makes sense that it would not ask that question when you power up the PC with the recovery media in place as it has already been specified.

Ian