Convert MBR to GPT without losing data

[ranchhand]

Hello all...I am in the middle of trying to build a computer that will upgrade to Windows 11 (from Windows 10).
Ran in to an unexpected problem....my main SSD is the BIOS MBR, and I am told it must be GPT.
That's not hard to do, Except that I will lose all programs/data because the drive will be wiped. Yes, I could reinstall all, but....I sure would like to avoid spending 2 days doing it.
So I ran across Easues partition tool that claims to be able to do it easily including all data & programs.
So my question: has anyone used Easues to convert his drive to GPT including all programs and data? (or any other app that works).
Thanks much....

[johns0]

Google how to convert mbr to gpt without losing data and you will find how to convert without needing to use Easues.

[ranchhand]

Thanks Johns....yeah, I Googled that, kind of iffy and complicated. Maybe I'll try Easues.

[krykmoon]

For any operation on partitions I suggest this free tool : https://macrorit.com/partition-magic-manager/free-edition.html

An old school compact and very efficient software easy to use and without crappy online "services"

The free edition has EVERYTHING (OS migration included), it's more than 10 years I'm using to do any kind of operation on partitions (split, resize, convert, OS migration) and it never failed me once.

There is also a portable version. Best partition manager on Windows for me.

[ranchhand]

Thanks Krykmoon, I will give it a look. I never did this, so I'm a bit shakey. This Asus ROG STRIX board I got has given me a lot of headaches, I am half way to sending it back to Amazon. I was several times on the phone with Asus support, and I got some bad advice that needed correcting. I finally updated the BIOS to where W10 will boot off my SSD, but Secure Boot will not activate. I am assuming that it is because my SSD is MBR formatted. If I succeed in converting it and Secure Boot will still no activate, the board goes back.
Thanks again..

[EDIT]: Ok, question....Looks impressive; It has a lot of specifications on the left panel which is pretty impressive; but I don't see where it specifies that it will convert from MBR to GPT while maintaining data; am I missing something?

[krykmoon]

Ok, question....Looks impressive; It has a lot of specifications on the left panel which is pretty impressive; but I don't see where it specifies that it will convert from MBR to GPT while maintaining data; am I missing something?

You have to select the whole hard drive, not the partition (because it's a change to the structure of the whole drive file system)

https://macrorit.com/help/mbr-gpt-convert.html

PS: this partition manager is by far the best for Windows. And the free edition is REALLY complete in features, not a joke (as often happens, with most of those - pseudo - "free" tools).

Worth buying other editions only to support Macrorit, that AFTER DECADES it's still giving all of this for FREE: a light, powerful, easy to use, up-to-date and COMPLETE software with no crap or shit added.

[ranchhand]

Question: Looks good, but just a clarifying queston: so, can I convert MBR to GPT on my Windows drive? I get different instructions on the website, some say "only use this on a disk not containing Windows", and the other at the bottom of your website link says I can use it to convert the Windows partition/disk to GPT.
Note your link at the bottom of the page...
"Convert MBR to GPT without data loss in Partition software is needed when system partition and other logical partition are set on disk, and you don't want to delete any partition before conversion. "
Have you yourself actually used this to convert a complete Windows drive to GPT?
Thanks, I'm not trying to be a pain, just making sure...

[The_Doman]

This is a good video about it:

Youtube: Britec09: How To Convert MBR To GPT For Free In Windows 10

Remember this always is still a risky operation if something unexpected goes wrong!
Specially if you not have experience and/or a fallback PC system available.
Best would be to make a system/backup clone of the drive or at least of your most important stuff.

[krykmoon]

Question: Looks good, but just a clarifying queston: so, can I convert MBR to GPT on my Windows drive?

If you mean the ACTIVE partition.. (where your running OS is).. no, there's no way to rewrite the disk partitions table when you booted from it.

You can do it booting from another disk (the OS you use for the conversion must be installed elsewhere, not on the disk you intend to convert) or from a so called "rescue cd", like this (PS: it also has Macrorit Partion Expert) :

https://www.hirensbootcd.org/

Keep in mind that even if tools like Macrorit Partion Expert are very reliable and safe something can always go wrong (power failure during a critical operation.. OS components/dlls crashes... ) and so a backup of the disk/partition would be always advisable (*)

(*) I never made backups before using Macrorit.. and I never had problems with it... but that's not a good practice, anyway. If you have critical data you can't absolutely afford to lose .. backup them before.

[ranchhand]

THANKS!...glad I asked! So I will use Rufus to create a bootable flash drive and run it from that on my main SSD drive, right?
And...thanks Doman, I will review that video link.

[The_Doman]

THANKS!...glad I asked! So I will use Rufus to create a bootable flash drive and run it from that on my main SSD drive, right?
And...thanks Doman, I will review that video link.

Well, as it has been a while since I converted OS drives from MBR/Legacy to GPT and also to prevent possible disasters, I did some testing using the programs on the excellent Hiren's BootCD PE.
I recommend everyone should always have a USB like that available for unforeseen disaster situations!
I used a clean Windows 10 install/image in MBR/Legacy mode on my old trusty Dell Latitude E6410

If you mean the ACTIVE partition.. (where your running OS is).. no, there's no way to rewrite the disk partitions table when you booted from it.

You can do it booting from another disk (the OS you use for the conversion must be installed elsewhere, not on the disk you intend to convert) or from a so called "rescue cd", like this (PS: it also has Macrorit Partion Expert)

Macrorit Partion Expert did not allow me to do the conversion:


[Attachment 86839 - Click to enlarge]

I tried the Easus Partition Manager, also a good tool I use often, but It failed badly.
The system stayed bootable with MBR/Legacy mode but the resulting disk layout was made incompatible for the Mbr2gpt tool:


[Attachment 86840 - Click to enlarge]

Also I tried DiskGenius from the same Hiren's BootCD, it converted the disk but not the system/boot files resulting in a unbootable system disk.

Then I used the official MBR2Gpt tool:

Youtube: Britec09: How To Convert MBR To GPT For Free In Windows 10
Reddit: Can't convert Hard Drive from MBR to GPT?

If you’d like to keep your data, you’d need to use MBR2GPT or a third party partitioning software.

Open cmd in admin mode

Type mbr2gpt /allowFullOS /validate /disk:<disknumber>

Type mbr2gpt /allowFullOS /convert /disk:<disknumber>

Step 2) runs a validation check on the disk and gives you information on the disks’ eligibility for the conversion, this step is optional. Step 3) does the actual conversion. <disknumber> is the number of the disk noted in step 3) of the diskpart process prior to this section.

MBR2GPT can be used on a disk that contains an Operating System. If doing so, it’s recommended that you run the tool from cmd available when you boot into advanced startup options. When doing this, you don’t need to use the /allowFullOS.

I tried both from a full booted Windows system and from the recovery/advanced startup options.
It converted the disk without problems and the system booted fine in UEFI mode.
Only with a minor error message about Reagent.xml which seems to had no side effects.


[Attachment 86841 - Click to enlarge]

Also/better you can use the MBR2GPT tool from the Hiren's BootCD PE.
Worked perfectly fine too and NO error message at the end.


[Attachment 86842 - Click to enlarge]

But still, always make sure you have backups and may be disconnect extra drives temporarily to be sure you selecting the correct disk!.

[ranchhand]

@Doman....thanks for the update and testing. So...is there a way of loading the Hirens boot CD to a flash drive?

[ProWo]

Minitool Partition Wizard Free portable should do it without all this extra work.
Google for it.

[The_Doman]

@Doman....thanks for the update and testing. So...is there a way of loading the Hirens boot CD to a flash drive?

Yeah, of course you can, do not get confused with the Hiren's bootCD naming.
Burning on CD/DVD we did in the old Win9X/XP days.

It is all there explained on the site.
But make sure you EXACTLY follow the instructions about "Dual UEFI/BIOS" booting to be able to use the USB on BOTH UEFI and MBR/Legacy systems!

Hiren’s BootCD PE: USB Booting

Activate Dual UEFI/BIOS mode

With Rufus open, press ALT+E to activate Rufus's "Dual UEFI/BIOS" mode.

(This mode is initially inactive within Rufus. Ensure that the message "Dual UEFI/BIOS mode enabled" appears at the bottom of the program. After activating the "Dual UEFI/BIOS" mode, the setting is saved in Rufus's configuration so you won't need to enable it each time).

Note: Please activate the "Dual UEFI/BIOS" mode first and then select the ISO file. Otherwise, the FAT32 format cannot be selected within Rufus.

Also , it is STRONGLY advised to use a decent ad-blocker/browser to make navigation/download on that (and other) sites easier/safer.