Windows 10: Partition Prerequisites for converting to GPT using MBR2GPT

Thanks topgundcp. That is a relief.

Tracey

 

Hi All

Having read all the responses to my initial post let me see if I have it straight in my own mind. To do the conversion (and my current Disk 0 layout minus Windows 7 is OK -- I've already checked that) I believe I have to carry out the following procedures in the order given:

1. Backup the whole drive
2. Delete the Windows 7 partition
3. Convert all HDs and SSDs to GPT
4. Run MBR2GPT to do the conversion
5. Access the UEFI firmware and set to UEFI mode
6. Reboot

Regarding No.3 -- I believe that the OS disk remains as MBR as BIOS cannot have the OS on a GPT drive am I right on that?

You know, thinking about it, there's seems to be an awful lot on this forum about converting to UEFI but it all needs to be brought together in one post or perhaps a PDF so that people can see for themselves exactly what you need to do to take advantage of the new technology. However, I believe it needs someone with an awful lot more knowledge about PCs than I have to do that. It's just a thought as it's been a struggle trying to find out what is needed and the order in which the procedures should be done. After all there is so much that could go wrong and you could finish up with an unusable PC if you DO get it wrong.

Could someone please check the process I have given above and tell if I have gone wrong anywhere -- PLEASE?

Tracey

 

Delete step 3. Step 4 will convert the system drive to GPT and convert the System Reserved partition (which legacy BIOS boots from) to an EFI System Partition (which UEFI boots from). After MBR2GPT completes that conversion, your computer will no longer boot in legacy BIOS mode. You will need to set the UEFI firmware to boot in UEFI mode before the computer will boot into the OS again.

After the system drive is converted to GPT and is booting in UEFI mode, then you can convert the other physical drives to GPT if you want to using third party partitioning programs like MiniTool Partition Wizard or AEOMI Partition Assistant.

After you backup your drive, presumably with a program like Macrium Reflect, make sure to also create the rescue drive (USB flash drive) with the same program so that you can boot the computer from that to restore the backup image if you need to. The rescue drive should be bootable in both legacy BIOS and UEFI modes.

I'll work on the steps to do the conversion manually and setting up your own EFI System Partition from scratch. I'm going to make a backup of my computer and do it myself to make sure I get the steps correct.

 

From what you are saying, if you can convert non-OS disks to GPT after conversion I assume that UEFI will read MBR disks.

What I gather you are saying is that the following is the procedure to adopt using MBR2GPT:

1. Backup the whole drive
2. Delete the Windows 7 partition
3. Run MBR2GPT to do the conversion This converts the OS disk to GPT
4. Access the UEFI firmware and set to UEFI mode
5. Reboot
6. Convert all remaining HDs and SSDs to GPT

I'll hang fire before trying anything to see what you would recommend re doing things manually. As far as the Mobo settings are concerned (and I've not mentioned them so far) -- I seem to have only some (perhaps only one) of the expected options as follows (its a Gigabyte Z97P-D3) showing the default settings after the double dash:

Boot Mode Selection -- UEFI and Legacy
LanPXE Boot Option ROM -- Disabled
Storage Boot Option Control -- Legacy Only
Other PCI Device ROM Priority -- UEFI OpROM
Network Stack -- Disabled

Any idea how these should be set. There is no CSM or Secure Boot options that I can set , at least, not that I've found them yet!!!

 

Here's the recommendations from Microsoft:
UEFI/GPT-based hard drive partitions | Microsoft Docs

My steps will not create any recovery partition, and will delete all existing recovery partitions. That's just something to be aware of. The next time your computer does a major build upgrade of Windows 10, such as the Fall Creator's Update, it will likely recreate the recovery environment, either by making a new recovery partition or by inserting into a hidden/system folder C:\Recovery. I've got my system image backup made of Macrium Reflect Free of my entire SSD. Now I'm going to boot into Macrium Rescue Environment and wipe my SSD, create the required partitions with GPT partitioning on the SSD. Restore my OS partition and create the boot files

Be back in a couple hours!

I think you can leave those set just the way they are. CSM option is the same as the Legacy option under Boot Mode Selection. You won't have Secure Boot available unless you set Boot Mode Selection to UEFI only.

 

Note to self...always verify the backup file. I went to restore the backup file I had created for this project, and it was corrupt. :-( So, now I'm posting a fresh, clean install of Windows 10 on my desktop computer.

Create a disk image backup of your existing HDD - mine is an SSD. And VERIFY the backup image!
Then boot from Macrium Reflect Rescue media - either a USB flash drive, or the boot menu rescue option if you created it.
In the lower left of the task bar is an icon for command prompt. Click on that to open a command prompt.
Run the following commands:

diskpart
list disk
select disk # <- replace # with the actual number of the system drive you want to convert and restore. Probably 0.
clean <- this will erase the physical drive selected above. Make sure it is the correct drive!
convert gpt
create part efi size=100
format fs=fat32 quick
assign letter=t
create part msr size=16
exit
exit

Now you should be back in Macrium Reflect. Click on the Disk Image tab. Then View in the menu, and Refresh. Then click back on the Restore tab. Now select the image file you created, click on the option to restore in the menus to the right of the image file name. In the bottom half of the screen should now be something like select target drive, click on that. Select you system disk, which should now be showing the EFI system partition you created, the MSR partition, and unallocated space after that. Drag and drop your OS partition ONLY from the image file to the unallocated space on the system disk. Click the finish button or whatever button it is to do the restore operation.

After the restore is complete, make a note of the drive letter that was assigned to the destination partition. It should be C:. Click the Command Prompt icon again and run:

bcdboot C:\Windows /s T: /F UEFI

The drive letter in red is whatever Macrium assigned to the restored partition.

Now restart your computer and make sure to "spam" (repeatedly press) whatever key you need to to get into your UEFI settings. You might have to re-adjust your boot priority list to put "Windows Boot Manager" on your system drive back to the top of the list. Then restart and you should boot into your previous Windows installation.

 

Thanks for the info NavyLCDR. Very much appreciated.

Sorry to hear of your problem with your Macrium backup. I too use Macrium and so far the number of times I've needed to access a backup have been few and far between. So far I've been lucky. However, I will take note of your caution and verify my backups in future. Good luck with your reinstall.

As for the process you adopt to manually create a UEFI system I think I follow all the commands and would not be averse to doing it that way myself if needs must. Nevertheless, I think I'll give MBR2GPT a try first and see what that does. If you don't mind though I'd like to extract the text and save it on my PC for future reference should it be needed.

If I read you right the Mobo settings I've listed above will suffice and no changes should be needed. That's very good news. Obviously Gigabyte put some thought into their default settings. So it looks like I'm all ready to go. Perhaps I'll leave it until after I've done my backup on Saturday then go ahead.

Once again, thanks for all your help and good luck with your reinstall.

Tracey