Question WIndows 11 hardware support question, changing an existing SSD with partitions from MBR partition style to GPT partition style

[William Gaatjes]

Hi all, i have a computer that is capable of being windows11 compliant.

Of course, there is a caveat :
The only thing i have to do with a new fresh install, is convert the SSD form MBR to GPT. And disable in the bios the CSM module.
This to get the UEFI part of the bios to run with secure boot.

Is the program MBR2GPT.exe also present on the install USB stick that is created with the media creation tool ?


Can i just start with the cmd commandline using the install usb stick ?

Steps to take :

1 Erase all data on the ssd , remove the partitions.
2 convert the SSD from MBR to GPT through MBR2GPT.exe.
3 Then disable in the bios the CSM module.
4 Start again with the install usb stick
5 Install windows 11.

It has been a while with me installing windows.

 

[kn51]

Starting fresh? Set bios to uefi, nuke partitions during setup.

MBR2GPT will convert current MBR installs to GPT. Which then you have to flip to uefi half-way through. (Useful if doing an upgrade, but sounds like you are doing a clean install)

 

[William Gaatjes]

I see. Thank you.
Yes, i will be doing a fresh install, because of the MBR/GPT issue.
Making backups, remove partitions , converting MBR to GPT , restoring partitions and and writing the backups back is too much work.
My data disk is GPT already.
My main windows disk is MBR.

But i remember that in the past windows 10 would not install with some X80xxxxx error code and after converting my ssd to MBR , windows would install.
I did not know at the time that in my BIOS the CSM module was active and therefore UEFI was inactive and therefore installing W10 at the time on a GPT disk would fail and W10 setup came up with an X800xxxxx error code.
I just googled for the solution at the time and converting to MBR was written down as a solution at the microsoft support sites. It was not mentioned that UEFI needs to be active and CSM to be inactive, and that is the first option to be checked before converting the install disk to MBR.

Now, W11 needs GPT and i am having the same issue.

I do not know how the W11 setup progresses. I have never used it.

And i am very dependent on my computers at the moment.
I need to have the computer up and running within a few hours on the same day.

I am making a schedule with a list of tasks like making backups to make sure that i do not mis anything.

After that i will try using rufus + windows 11 on another pc .

 

[tecknot]

Hi William,

You can convert an MBR disk to a GPT disk simply by going into Diskpart (type in "Diskpart" at the prompt) in a command prompt (as administrator). Now type in "list disk," and select the desired disk by typing "select disk #" (just exchange the "#" with the desired disk number). Type in "clean" to delete all items and partitions from the disk. From there you can just type "convert GPT" and that will do it. Now you just create the desired partitions and format. (Let me know if you need instructions for Diskpart.) See screenshots attached.

Kind regards,

tecknot