Windows 10: Converting a hard drive from GPT to MBR.

I want to convert my GPT hard drive to mbr. I'm using a bootable USB ISO. Just one OS (Windows 10 - 20H2). I have followed these instructions and they seem to have worked (when I reopen the command prompt the mark under gpt disappears). Problem is once Windows install and I look using the command prompt it shows the hard drive as gpt once again. Is it possible that the conversion to mbr does happens but once Windows starts installing it switches back to gpt by default?

:)

 

Converting a hard drive from GPT to MBR.

Managing disk partitions is a risky task. Make sure you have all your data backed up.

What do you want to do:
- Convert a data drive from GPT to MBR?
- Convert a boot able drive from GPT to MBR?
- Do a clean install using a win 10 installation drive and convert the drive from GPT to MBR?

If it is a data drive you can convert from GPT to MBR.
Diskpart commands will clean up the drive. To convert without loosing data you must use a program like Mini Toll partition wizard .

But if the drive is a boot able drive, you can't just convert from UEFI - GPT to Legacy - MBR. You have to make sure your BIOS can use Legacy boot drive.
You have to boot from an external drive (like WinPE), launch Mini Toll partition wizard, convert from GPT to MBR and rebuild bcdboot.

diskpart
list volume (take note of windows partition letter)
select volume x (replace x with the windows partition letter)
active
exit
bcdboot C:\Windows /s C: /f BIOS
exit

 

Convert only one partition on the disk from MBR to GPT

Step 2
Convert MBR to GPT without data loss

 

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.