mbr2gpt error: Unrecognized partition found, index 2

Windows 10.0.18363
I have 1 SSD (1TB) and 2 hard drives (3TB and 1TB), as per disk manager screenshot below. I was dual-booting with Win10 and Ubuntu 16.04 before a Win upgrade made the dual-boot inoperable.
Disk 1 is a 1TB SSD, which is where I'm booting from. It was using 500GB for Win and 500GB for Ubuntu. It is MBR.
Disk 0 is a 3TB hard drive which I was using strictly for Windows. It is GPT format.
Disk 2 is a 1TB hard drive which I was reserving for Ubuntu. It is MBR (ext?).



I want to convert all disks to GPT. I merged the Linux partition on disk 1 into my Windows partition on that disk. mbr2gpt thinks I still have 4 partitions on that disk, while disk manager does not. mgr2gpt fails with previous error message (logs below).

I have read previous tutorial and posts in this forum, but have not found a solution yet. Any help greatly appreciated.

setupact.log

setuperr.log

You can also backup the OS partition on disk 1 using a program like Macrium Reflect. Completely erase (clean) disk 1 and convert it to GPT. Manually create an EFI System partition it, then restore the backup image of the OS to it.

NavyLCDR, drive 1 is a boot able drive. It has to be converted AND create a EFI fat 32 partition.

Megahertz said:

NavyLCDR, drive 1 is a boot able drive. It has to be converted AND create a EFI fat 32 partition.

OK. And that was pretty much exactly what I posted in post #3.

To wit:

NavyLCDR said:

You can also backup the OS partition on disk 1 using a program like Macrium Reflect. Completely erase (clean) disk 1 and convert it to GPT. Manually create an EFI System partition it, then restore the backup image of the OS to it.

For a more detailed explanation:
1. Back up the OS partition to one of the other drives.
2. Use diskpart commands to clean disk 1 and convert it to GPT.
3. Use diskpart commands to create an EFI System Partition (ESP), 100 mb will do, format it FAT32, and assign a drive letter to it.
4. Restore the backup image of the OS to the remaining unallocated space on the disk.
5. Use the bcdboot command to write boot files to the EFI System Partition.

NavyLCDR said:

OK. And that was pretty much exactly what I posted in post #3.

To wit:



For a more detailed explanation:
1. Back up the OS partition to one of the other drives.
2. Use diskpart commands to clean disk 1 and convert it to GPT.
3. Use diskpart commands to create an EFI System Partition (ESP), 100 mb will do, format it FAT32, and assign a drive letter to it.
4. Restore the backup image of the OS to the remaining unallocated space on the disk.
5. Use the bcdboot command to write boot files to the EFI System Partition.

How is he going to do all this commands if he only has one boot able drive that you're saying it has to be cleaned?
To do it, he must have another boot able drive (like the rescue drive).
Why not just clean the Linux partitions and use mbr2gpt?

Megahertz said:

How is he going to do all this commands if he only has one boot able drive that you're saying it has to be cleaned?
To do it, he must have another boot able drive (like the rescue drive).
Why not just clean the Linux partitions and use mbr2gpt?

He certainly can do that. I'm just posting an alternative.

Another alternative based on NavyLCDR suggestion.

- Boot from the Rescue disk and create a disk image using Macrium Reflect and save it to another drive.
- Enter BIOS and select UEFI mode and set fast boot and secure boot to disable.
- Detach all other drives from MB (SATA or Power cable)
- Boot from a Win 10 installation drive (same version) as UEFI, not Legacy, go to install, delete all partitions on the SSD and proceed.
- Windows will be installed as UEFI-GPT and the drive will have 4 partitions
_ One 100MB Fat32 EFI partition
_ One "other" 128MB
_ One NTFS C: partition with Win 10
_ One 600MB NTFS recovery partition.

- Boot from the rescue disk and with MiniTool partition delete the C: partition just created on the SSD
- Run Macrium Reflect and restore only the C: partition from the image to the unallocated space created on the SSD. Adjust the size of the partition to the size of the unallocated space.

Done

Thank you both for your suggestions. Unfortunately, before I could start, my pc quit booting, showing a NTFS file system error.

Any idea why disk manager shows 3 partitions and mbr2gpt shows 4?

Thanks again, will repost when/if I am ever successful.

Windows Disk Manager doesn't show all partitions.

Better use MiniTool Partition Wizard