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.

[ranchhand]

@krykmoon....and anyone else who wants...
Well, I tried M/Soft's MBR2GPT. It's actually a lot easier than it first appears, there are really only two cmd's that you need type. It ran ok, but coughed up an error: "cannot find OS partition for Disk0". Well, my computer has no problem booting Windows from that partition, so......(?). I Google searched around and generally a lot of "we don't know why" stuff, so that door slammed shut. Ok, I created an ISO using Anyburn (free) of Macrorit and tried to use Rufus 4.7 (latest) to load it. Rufus returned, "cannot mount image, either flawed or unknown compression system". Well, my computer has no problem booting the program straight from the ISO.
So I am going in circles here. Can you (or anyone) suggest an IMG creation app that might work?
I suspect that I am going to have to buy a new NVme drive and pre-format it to GPT then install all my programs.

[krykmoon]

Ok, I created an ISO using Anyburn (free) of Macrorit and tried to use Rufus 4.7 (latest) to load it. Rufus returned, "cannot mount image, either flawed or unknown compression system". Well, my computer has no problem booting the program straight from the ISO.
So I am going in circles here. Can you (or anyone) suggest an IMG creation app that might work?
I suspect that I am going to have to buy a new NVme drive and pre-format it to GPT then install all my programs.

I can't understand exactly what you did.
What you mean when you say " I created an ISO of Macrorit" or "booting the program straight from the ISO" ?

If you can boot from the ISO you don't need Rufus at all.

I'm a bit confused.

[ranchhand]

Sorry....You are confused because I am confused! Sorry, guess I was in too big a hurry.
My comment: "booting the program straight from the ISO".
I did not mean that the ISO would boot from a thumb drive on rebooting Windows. What I meant is that the ISO I created of Macrorit (using Anyburn) will load and run if I double-click on it while running Windows, so I can't see how the ISO is faulty. However...when I attempt to load that ISO onto Rufus, Rufus will not accept it, returns the error message, "cannot mount image, either flawed or unknown compression system". So I have no way to run it from outside Windows.

I also tried to use Macrorit Partition Expert from within Windows but it failed with the same error message that The Doman has posted (see the picture he uploaded) "this disk contains system boot volume so cannot convert or system will not boot" (or something like that).

I have tried Microsoft's MBR2GPT tool from within Windows and it failed twice. Messaged "cannot find OS partition for Disk0".

So I was asking if anyone can recommend an image creation app that worked for them. Anyburn did not work for me.

[The_Doman]

Oh, it was already too long too quiet.

I also tried to use Macrorit Partition Expert from within Windows but it failed with the same error message that The Doman has posted (see the picture he uploaded) "this disk contains system boot volume so cannot convert or system will not boot" (or something like that).

Yes, and that is good thing too it does not allow you to do it!
Macrorit can not do the conversion without making your system unbootable.
I don't know what/how what ISO you made/tried, but I even tested it with the Macrorit Partition Expert WinPE 8.6.0 Technician Edition ISO/USB, it will give the same warning.
It is just not the right tool for it!, do not use it for this situation!

I have tried Microsoft's MBR2GPT tool from within Windows and it failed twice. Messaged "cannot find OS partition for Disk0".

Possible your NVME SSD drive has another disk number?
Possible you have multiple Disks/SSD's in your PC?
Or another unexpected situation which we can not see/know at this moment.
When I search for "MBR2GPT cannot find OS partition for Disk 0" there can be various causes for this message/problem.
Probably this can this can be fixed, but without some experience with these kind of situations you can quickly loose your data or bootable system.
At this moment do not just (repeatedly) try random things/programs without knowing exactly what you are doing.

I would first start making a working bootable USB from the Hiren's BootCD PE from the earlier instructions.
Just as test/backup option to see if you can make it work for you.

[krykmoon]

I did not mean that the ISO would boot from a thumb drive on rebooting Windows. What I meant is that the ISO I created of Macrorit (using Anyburn) will load and run if I double-click on it while running Windows, so I can't see how the ISO is faulty. However...when I attempt to load that ISO onto Rufus, Rufus will not accept it, returns the error message, "cannot mount image, either flawed or unknown compression system". So I have no way to run it from outside Windows.

Ok, I see the issue, now.

In anyburn you populated a list of files (those of macrorit) and then you created an iso of it, right ?
If this is the case.. that's why Rufus doesn't work with your ISO.
Your ISO is valid and can be mounted or burned, but it's not a bootable ISO and so it hasn't a booting partition table - and that's why rufus refuses to work with it -

Rufus was created because all those bootable images you can find (Windows and Linux Distros included) ARE bootable CD Images that you can burn on a physical CD but you can't use directly from a (much faster and practical) USB flash memory/pen drive. That's what Rufus does and its main purpose.

If The_Doman has tested Macrorit from a PE without success then it's also not an option anymore (iI can't exactly remember .. but it's possible that I did the MBR->GPT conversion with macrorit BEFORE installing the OS on the SSD that time I needed it, and that's the reason why it worked).

You have to stick with the official tool by m.soft.
Can you post a screenshot of macrorit partition manager listing your current drives/partitions ? It could help understanding what's happening and what to try to do now.

Anyway.. make a backup of all the data you can't risk to loose.

[Kakujitsu]

Disk Genius

[krykmoon]

Disk Genius

Have you tried it personally ? On the ACTIVE Booting partition where the OS resides ?

I watched a couple of videos and they're quite.. unclear (to say the least).

And in the comment section there are only comments of people that used the tool and lose all their data or made the drive not bootable.
See here for yourself: https://www.youtube.com/watch?v=DY7YZKkTbMI

Be VERY careful, ranchhand.

PS: it is NEVER advisable to do operations and changes on the current active and mounted partition where the OS resides, it's always better to boot from another disk or from a PE distro put on a USB stick.

[ranchhand]

Thanks to both! Yes, I noticed that Disk Genius has a cloudy reputation.
OK, well, so I created a bootable thumb drive (using Rufus) with an ISO of Microsoft's MBR2GPT, and booted it. Same thing, it cannot find the OS on my drive. I have attached a picture of the result. I tried targeting both Drive0 and Drive1, and it will not validate. I always get the same result with whatever tool I try. Really strange...my drive is working perfectly, in years never had a problem. There must be something that is side-tracking the access.
Just a thought....I read recently on one website that conversion needs three partitions, and I have only two. Anyone heard anything about that?

[Attachment 86892 - Click to enlarge]

[ProWo]

Just a thought....I read recently on one website that conversion needs three partitions, and I have only two. Anyone heard anything about that?

No, you have 2 disks.

To see the partitions, start diskpart again and type the following, hit Enter after any row:

sel disk 0
list part

This lists the partitions on disk 0

To see the partitions on disk 1, type the following, hit Enter after any row:

sel disk 1
list part

To see all volumes, type:

list vol

BTW:
For your MBR to GPT conversion have you tried Minitool Partition Wizard free version (portable)?
https://www.partitionwizard.com/partitionmagic/portable-partition-magic.html

[krykmoon]

I was asking for the same thing.. a list partition command from diskpart (also a screenshot from macrorit would suffice) to try to figure out what the issue could be.

[The_Doman]

Disk Genius

NO!, it can only convert the disk but not the system/boot files!
Without any warning it makes your system disk unbootable!

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.

[The_Doman]

For your MBR to GPT conversion have you tried Minitool Partition Wizard free version (portable)?
https://www.partitionwizard.com/partitionmagic/portable-partition-magic.html

Unfortunately, the free version only supports basic operations.
When you choose the MBR to GPT operation it connects to their webpage to buy the full/pro version.
The full version seems to do the job correctly, what i could test from some "other sources" on the net.

But then again, when the basic MBR2GPT tool fails, no idea of other tools can fix it automatically?
It has to be fixed/corrected manually, possible a simple task for the experienced user, but very risky for inexperienced users.

No, you have 2 disks.

Often with 2 disks you you can have the boot part on one disk and the Windows system on the other disk.
Always very annoying situation.
That why it is often advised to disconnect extra disks when doing a new Windows installation.

[ranchhand]

Good grief, you guys just triggered my memory.
I'll try to keep this brief. We're going back many years, now; I upgraded (retail version) from W7 to W8 to W10.
8 to 10 was a train wreck; trashed my OS. Did a repair reinstall, all was good except my Windows key # was not recognized. Long story short, I had to call M/Soft and actually got an air-breather (!) and after 40" of trying stuff, he said my key was in the database so I definitely was legal, but was marked inactive and he didn't know why. Put me on hold for about 5" then came back and said they were going to issue a "custom" key to me. Said twice in the conversation not to lose that key because there would be no record of it with M/Soft if I ever needed to reinstall my OS.
Honest, guys, I couldn't make up anything like this.

Now, for the last several years, I have no problems. However.....whenever I boot up the system, I get an options screen to choose Windows7 or Windows10 to boot in to. Well, there is no W7 so I boot W10 with no problem. I'm so used to doing that I don't even think about it anymore. HOWEVER.....if I do choose 7, I get the following system message (picture below); anyone have a thought? (@ProWo post #23)...I'm going to try your suggestion).
[EDIT]: just click on the pic and it will be right-side-up (?) Oh,well, whatever works

[ranchhand]

Here is a breakdown of my disk, I only have 1, not 2 as I see it; the top message is left over from when I tried to list disk 1. No such disk.

[Attachment 86897 - Click to enlarge]

[ProWo]

Here is a breakdown of my disk, I only have 1, not 2 as I see it; the top message is left over from when I tried to list disk 1. No such disk.

[Attachment 86897 - Click to enlarge]

Your pic in post #22 shows 2 disks.
Both are MBR Disks, not converted to GPT

The pic above shows the partitions of disk 0

Partition 1 is the system partition      (letter E:)
Partition 2 is your Windows partition. (letter C:)

For all further actions the only disk you should care is disk 0.

[The_Doman]

For all further actions the only disk you should care is disk 0.

We are not sure if there are more disks.

@ranchhand

Please also show a complete overview/screenshot of your Windows Disk Manager.
At least one partition should be marked as active, that is where the system boots from.
That can give us some more/better understanding what is going on, hopefully.