How to make active@boot disk bootable on uefi/gpt?

Matthew Wai said:

1. Boot from the HDD containing installed Windows and use AEOMI to covert MBR to GPT. Shut down Windows.
2. Boot from the USB drive containing Windows setup files in the UEFI mode.
3. Clean install Windows.

Does that work?

No. You would be trying to convert a system drive to GPT and most programs (including AEOMI, I believe) won't let you convert a system drive to GPT. You have to do the conversion when booted from another drive other than the one you want to convert.

Matthew Wai said:

I just found that someone had lost all the data after converting MBR to GPT using AEOMI.
See How to Convert GPT to MBR or Convert MBR to GPT without Losing Data?
Scroll down to Muh Wahyudgi's post.

Who knows how he lost his data. I doubt it was only from converting from MBR to GPT. It's always a good idea to have a backup of data before doing anything major to the drive it is on.

Do you think the following works in my case? I have a Linux live DVD containing GParted.
How to convert MBR partition table to GPT without data loss

But the free version does not have that function.

genet said:

You need to choose the FAT32 file system, if you want UEFI Boot Mode compatible USB flash drive.

Ten-odd minutes ago, I successfully booted my PC in UEFI mode from a USB flash drive with an NTFS partition containing Windows 10 installation files.

The UEFI specification does not require a UEFI computer to boot from NTFS. The specification only requires the computer to boot from a FAT file system. Therefore, relatively few UEFI computers will boot in UEFI mode from NTFS.

http://www.uefi.org/sites/default/fi...I_Spec_2_7.pdf

Printed page 593, electronic file page 663 and also printed page 597, electronic file page 667.

NavyLCDR said:

Therefore, relatively few UEFI computers will boot in UEFI mode from NTFS.

Actually, my UEFI computer is a low-end product which will do so.

NavyLCDR said:

The specification only requires the computer to boot from a FAT file system.

I failed to boot it from exFAT.

Matthew Wai said:

Actually, my UEFI computer is a low-end product which will do so.

I failed to boot it from exFAT.

From the UEFI specification:
13.3.1.1 File System Format
The EFI firmware must support the FAT32, FAT16, and FAT12 variants of the EFI file system. What variant of EFI FAT to use is defined by the size of the media. The rules defining the relationship between media size and FAT variants is defined in the specification for the EFI filesystem.

13.3.4.1 Removable Media
Removable media may contain a standard FAT12, FAT16, or FAT32 file system. Booting from a removable media device can be accomplished the same way as any other boot.


It's up to you to use what type of filesystem you want to try, but only FAT32, FAT16, and FAT12 are required to be supported in the EFI system partition or bootable removable media such as USB flash drive.