Re: Is it possible to dual-boot both MBR & GPT without changing BIOS settings on laptop

On 2025-11-11 13:19, Java Jive wrote:
>
> On 2025-11-11 03:45, Paul wrote:
>>
>> On Mon, 11/10/2025 7:27 PM, Java Jive wrote:
>>>
>>> Perhaps next I might try seeing if I can boot W11P from the original 
>>> MBR menu, which would achieve the desired state of only needing one 
>>> boot menu.
> 
> Had a go at that meantime, couldn't get it to work.

Still no success with this business of trying to boot Win11P on a GPT 
disk from Grub launched from an MBR disk.  This is what I've tried ...

menuentry 'Windows 11 Professional (on /dev/sdc2)' --class windows 
--class os $menuentry_id_option 'osprober-chain-65153A0C0A7F9BDA' {
	savedefault
	insmod part_gpt
	insmod ntfs
	set root='hd2,gpt2'
	if [ x$feature_platform_search_hint = xy ]; then
	  search --no-floppy --fs-uuid --set=root --hint-bios=hd2,gpt2 
--hint-efi=hd2,gpt2 --hint-baremetal=ahci2,gpt2 65153A0C0A7F9BDA
	else
	  search --no-floppy --fs-uuid --set=root 65153A0C0A7F9BDA
	fi
	chainloader /BOOTMGR
}

The above is what seems to get slightly furthest, but it fails with ...

         error: invalid signature
         Press any key to continue...

I've also tried both of the following ...

         chainloader +1
         chainloader /BOOTSECT.BIN

... where /BOOTSECT.BIN is a dd dump of the first sector of the Win11P 
partition, but both simply end up with the PC rebooting.

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