How to make MBR HDD bootable in UEFI mode?

Question

I have a PC that does not support booting from internal MBR HDD. Currently, it seems only to support booting from GPT partitioned HDD in UEFI mode. It does support booting from external MBR HDD if I turn off the security boot option and enable the legacy boot. I want to move an MBR HDD with Windows 10 installed from an old PC to this PC as an internal HDD. How can I manage it to be bootable?

It is impossible to convert the MBR partitions to GPT partitions using the MBR2GPT tool probably because it has an extended partition and logic disks. Maybe it is also impossible to use this method because the system reserved partition is smaller than 200M.

• DrMoishe Pippik: Possible workaround: Image the HDD, then remove all partitions and install Windows 10 from ISO, as GPT. Finally, restore the Windows partitions from image, overwriting that from ISO.
• DrMoishe Pippik: Image the disk using any tool, such as Macrium Reflect or dd, not as ISO. The Windows 10 ISO is downloaded from Microsoft. Restore with same tool used to make image.
• JW0914: @DrMoishePippik Reinstalling Windows wouldn't be necessary, simply apply the WIM after capturing it. There's no reason to use third party imaging tools when Windows natively supports this and does so without all of the problems that come from third party solutions, which the native solution [WIMs] doesn't have.
• JW0914: @William Boot a Windows Install USB, opening a terminal once the GUI loads via Shift+F10, capture an image of each data partition (Step 1), as well as the WinRE partition, saving the WIMs to another drive, follow Steps 1 - 6 at the bottom of that answer, then apply the WIMs to their respective partitions (Step 2 at the top of the answer)
• DrMoishe Pippik: @JW0914, Really?? Please let us know how to make a complete drive image, not a system backup, using native Windows tools! The purpose of a drive image is to safely store everything on the drive, not just system files, so one can recover in the event of drive failure or damage to any or all partitions.

Answer 1

Here is what I did in the past.

I then made a bootable gparted ISO made a USB key and booted from it.

I got a 2nd drive, and formatted GPT.

Then I created a 100MB FAT partition, and left it empty for later use.

After that I did a copy and paste of each partition into the new drive. You may have to reduce the size of the partition depending on the size of a new drive.

After all the partition actions are done, you have to hit apply and depending on what you did it may take hours for it to complete.

I don't remember what I did to get windows to actually use the UEFI partition.

When your all done assuming you didn't need to enlarge any partition you could use clonezilla or similar to clone everything back to the original drive.

These direction may help

diskpart
list disk
select disk # Note: Select the disk where you want to add the EFI System partition.
list partition
select partition # Note: Select the Windows OS partition (# number) or your data partition of the 100mb partition.
create partition efi size=100
format quick fs=fat32
assign letter=s
list partition
list volume Note: Note the volume letter where the Windows OS is installed.
exit
bcdboot X:\windows /s S:
Note: Replace "X" with the volume letter of the Windows OS partition.