MBR to GPT Partition Problems

So I want to convert from MBR to GPT to get ready for windows 11, and realistically I should be using GPT anyways, but I've cloned this drive like 5 or 6 times over the years as I've upgraded PC parts.



Anyways I cant use the tool in windows, or under command line, my drives look like this in disk manager, I'm assuming I dont have a partition for the O.S and thats why it wont work. Is there any way to fix this?



Here is a screenshot of disk manager: My disks in disk manager

spunk said:

Windows needs to create a couple of hidden partitions. Use a 3rd party app like Minitool Partition Wizard. You may need to shrink the C: drive about 1GB or so, to allow the creation of the hidden partitions, then use Minitool to convert to GPT.

I downloaded minitool, this is what I see in there: Imgur: The magic of the Internet

Should I shrink it by 8gb? I did a quick google search and the other virtual disk MSFT XVDD is appperently for some game pass games I have installed.

Edit: So I shrunk it by 2gb, I see only about 500mb is actually being used in the virtual disk. I restarted but the 2gb is just unallocated space, do I need to run some windows tool to do something with this, or do I need to format it to NTFS or something?

I'm just guessing here, but should I have 8gb unallocated space, then I copy the virtual partition to the 8gb unallocated via minitool?

spunk said:

In Minitool, go to Disk/Covert MBR to GPT. It should create a 500 MB Hidden Partition. Be sure to press Apply after each change. You may need to restart the computer as well. If you successfully converted to GPT, then Resize/Extend Disk 3 to fill out the remainder of the drive you shrunk. Be sure you have an Image backup of your Disk 3 before attempting in case things go wrong.
If that is successful you can convert Disk 1 and Disk 2

Crap, minitool wants me to pay to do MBR to GPT, is there any other way to do this? Could I use "rebuild MBR" through minitool and then use windows's own MBR to GPT?

The problem is that disk 1 has the system partition on it, and disk 2 has the OS partition on it. mbr2gpt requires that the OS and the system partition be on the same disk. You need to run:

Code:

diskpart
select volume c
active
exit
bcdboot C:\Windows /s C: /f BIOS

then boot the computer from disk 2. Once disk 2 is both the disk with the system partition and with the OS, then you will be able to run mbr2gpt on it.



"System" and "Boot" in the above screenshot need to both be on disk 2.

spunk said:

Now that you have the shrunk the C: drive, go back to Disk Management and right click Disk 3 and choose Convert to GPT Disk.
Or you can start a Command Prompt as Admin. And use Diskpart. 2 Methods: Convert Windows 10 MBR to GPT Disk without Data Loss
There are other Partition Managers like Aomei and Easeus, I am not sure if they convert for free, but you can give it a try.
Be sure you have a Drive Image file of Disk 3 saved to another drive before attempting any more changes.

It's greyed out in disk manager, I cant convert to GPT disk Imgur: The magic of the Internet

Command line gives me an error about not able to find any OS installations on the drive.

NavyLCDR said:

The problem is that disk 1 has the system partition on it, and disk 2 has the OS partition on it. mbr2gpt requires that the OS and the system partition be on the same disk. You need to run:

Code:

diskpart
select volume c
active
exit
bcdboot C:\Windows /s C: /f BIOS

then boot the computer from disk 2. Once disk 2 is both the disk with the system partition and with the OS, then you will be able to run mbr2gpt on it.



"System" and "Boot" in the above screenshot need to both be on disk 2.

Okay I'll try that. I opened command prompt, used diskpart command, it opened a seperate windoe I then selected volume C and used the active command, then exit closed the window. Now back in command prompt is where I run bcbbood C:\Windows ... etc correct?

My F drive is my old hard drive I basically use for nothing its very strange my system files are on it.