Question Is changing my boot drive from MBR to GPT pretty safe?

_dawn_chorus_

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Aug 30, 2017
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I am trying to confirm Win11 will work on my current setup (relevant specs: 8700k, Gigabyte Aorus Pro Z390, 970evo 1TB boot drive, 5x storage drives) and I have found I need to enable secure boot, which I cannot do because my boot drive is apparently MBR and needs to be GPT.

I found a video that makes it seem pretty easy to convert it, but I wanted to get some opinions on how safe it is to do this. Is there a reasonable probability it could fail? I really want to avoid doing a fresh install. I have all my data backed up but no actual mirror of my C drive which is just windows and installed programs.
 
Solution
i would back up anything you don't want to lose - thats generally good advice anyway

I don't see many people fail it

Colif

Win 11 Master
Moderator
i would back up anything you don't want to lose - thats generally good advice anyway

I don't see many people fail it
 
Solution
I found a video that makes it seem pretty easy to convert it, but I wanted to get some opinions on how safe it is to do this. Is there a reasonable probability it could fail?
It's safe. Yes.
But depending on your partition configuration it might not work.
There are some quite specific requirements for it.

Disk Prerequisites
Before any change to the disk is made, MBR2GPT validates the layout and geometry of the selected disk to ensure that:
  • The disk is currently using MBR
  • There's enough space not occupied by partitions to store the primary and secondary GPTs:
    • 16KB + 2 sectors at the front of the disk
    • 16KB + 1 sector at the end of the disk
  • There are at most three primary partitions in the MBR partition table
  • One of the partitions is set as active and is the system partition
  • The disk doesn't have any extended/logical partition
  • The BCD store on the system partition contains a default OS entry pointing to an OS partition
  • The volume IDs can be retrieved for each volume that has a drive letter assigned
  • All partitions on the disk are of MBR types recognized by Windows or has a mapping specified using the /map command-line option
If any of these checks fails, the conversion won't proceed, and an error will be returned.