Windows 10: Converting disk from MTR to GPT and installing Windows 11

Hello there,I want to update my OS from Windows 10 to Windows 11. For that I have to enable secure boot in my UEFI. After doing that my Computer always booted to the UEFI and not Windows anymore... everytime. On Reddit I found this solution: https://www.reddit.com/r/gigabyte/comments/qs9226/boots_only_to_bios_after_enabling_secure_boot/ My Question now is how do I convert from MTR to GPT? I read about it here: https://learn.microsoft.com/en-us/windows-server/storage/disk-management/change-an-mbr-disk-into-a-gpt-disk But I think this site doesn't consider the disk to be the same disk

:)

 

Cannot convert GPT to MBR.

Hi Michael,



I suggest you to follow the below steps and check if it helps.

This method you have to backup all your data and delete all partitions and volumes. Then use the
DISKPART command.

• Open command prompt and type in DISKPART and press Enter
• Then type in list disk (Note down the number of disk you want to convert to GPT)
• Then type in select disk number of disk
• Finally type in convert gpt.

Hope the information helps. Do reply if you need further assistance.

 

Converting a MBR disk to a GPT disk

I would put Windows on Disk 2. There is plenty of space. If you want to start with a clean slate then you should do this:

• Disconnect disks 0 and 1.
• Boot the machine with your installation medium.
• Launch diskpart.
• Select disk 0 (it was disk 2 before).
• clean.
• Reboot with your installation medium.
• Install Windows.
• When it runs nicely, connect the other disks and tell the BIOS which is the primary disk to boot from.

Since disk 2 is only 232 GBytes you will not need UEFI / GPT. After Windows is installed you can convert the 3 TByte disk to GPT.

 

Converting a MBR disk to a GPT disk

When installing Windows I was asked which drive to install it on and selected the 3TB drive, whereupon it stated it couldn't install it on there as it had a MBR and needed a GPT drive.

-> OK, with such a large disk you must use the GPT partitioning scheme.

I then tried converting it to a GPT drive using diskpart etc through the Cmd prompt with Admin privileges. But when I got to selecting the disk it told me I couldn't select it because it had a Paging
File.

-> I am not surprised.

Went online to get MS Technician to help me and he said go into the BIOS, press Ctrl-Shift-Delete keys and then Diskpart etc to convert the disk to GPT.

-> What he probably said is that you need to set the "BIOS boot mode" to UEFI.

The Windows installation process gives you the option of partitioning and formatting your disk. It probably lets you choose the partitioning scheme too, MBR or GPT. I do not know for sure since I do not
have a disk > 2 TBytes that I could test. If not then you can do this:

• Boot the machine with your installation medium.
• Select Repair Mode, then the Command Prompt.
• Use diskpart.exe to partition & format the disk.
• Install Windows.

You might ask yourself if you really want a 3 TByte System Partition. I would go for a 100 GByte System partition and a 2.9 TByte data partition.