Anybody have multiple bootable disks in their Secure Boot PC?

steve17 · Dec 8, 2021

RoadBlaster said:
I did not unplug one or the other NVME's when installing dual boot & both my copies of W11 work perfect, 1 on each drive & windows always sets it up like in my picture.

View attachment 15740

Yes, but only Disk 0 is bootable. If Disk 0 should fail, you couldn't run any OS. You wouldn't get the OS menu. Only Disk 0 shows up as a bootable device in the BIOS menu.

With my system, both of my M.2 devices are bootable. They both show up in the BIOS list of bootable devices. If either Disk fails, I can boot from the other and repair what's wrong.

Your way is okay too, but if the Disk 0 fails, you need to use a USB flash drive to fix it.

Here's my bootable device list:

FDretired · Dec 8, 2021

I had 2 operating systems on my desktop for a few years on separate ssds. Recently I would install windows 10 on a GPT as UEFI disk and second system which could be linux on MBR disc.

For windows 11 I upgraded my hardware ( ASUS PRIME B560-Plus) and in the new motherboard CSM is blanket out and can only be activated in there is password in the bios.

I needed an urgent copy of Windows 10 on the second disk to use my scanner and I did not want to mess up the boot options in the Windows 11 disk.

This my my amateur solution

I made a Macrium image of windows 11 on a third disk . I booted with EASEUS and deleted windows 11. I then did fresh installation of windows 10 on the spare disk.

I then restored win 11 with macrium reflect bootable disk

By default I boot into win 11

If there is a need for me to boot into windows 10 for any reason I will do it from the boot menus. My scanner is workng fine with Windows 11 and I now have very little reason to boot into windows 10 except to try some new software discussed in this forum example Mini Tools

NavyLCDR · Dec 8, 2021

It takes less than 1 minute to put an EFI system partition on a disk before installing Windows to the second drive. It would take me 15 minutes to get into the computer to physically disconnect a disk and risk breaking the little tabs that hold the back on. So guess which method I use?

If you want to install Windows10/11 to the second disk, and make it bootable, without removing the first disk. Boot from the installation USB flash drive, press Shift+F10 to open a command prompt. Then:

Code:

diskpart
select disk 1 (your disk number may be different)
clean
convert gpt
create part efi size=100
format fs=fat32 quick
assign letter=s
exit
exit

Then select the unallocated space on the rest of the disk and click on next to finish the install of Windows 10/11 on the that disk. Boot into your new Windows from the dual boot menu that will be created. Open a command prompt with admin privileges, run:

Code:

bcdboot C:\Windows /s S: /f UEFI

Done. No opening the computer, no disconnecting drives, I can do the above commands in less than 1 minute total.

steve17 · Dec 8, 2021

Yeah but you are superman.:) It easier for me to remove a thumbscrew and slide off the side panel of my computer. Then I can unplug an SSD.

FDretired · Dec 8, 2021

steve17 said:
Yeah but you are superman.:) It easier for me to remove a thumbscrew and slide off the side panel of my computer. Then I can unplug an SSD.

I used to do that in the past when there was lots of space around my desktop case.

I wondered whether it was possible to have external switch to turn off the power to second ssd.

NavyLCDR · Dec 8, 2021

FDretired said:
I used to do that in the past when there was lots of space around my desktop case.

I wondered whether it was possible to have external switch to turn off the power to second ssd.

Only if it is SATA

cereberus · Dec 9, 2021

If you want to create two independently booting drives i e. each with their own EFI, you do not have to disconnect first drive.

Here is a way to do it.

1) Make an image backup of EFI partition on 1st drive using Macrium Reflect or similar to a usb drive.

2) Create a bootable Macrium Rescue Drive.(or similar)

3) Create bootable Windows installation drive

4) Make sure second drive has enough unallocated space to install windows.

5) Remove the EFI from primary drive using tool like Mini Partition Wizard

6) Boot from usb installation drive and install Windows on 2nd drive.

7) Boot from Macrium USB drive and restore EFI partition to 1st drive.

You will now see two windows boot managers in bios and can select which boot manager you want.

You can optionally boot from one, and add boot entry to other ising bcdboot. Then you can do it the other way round if uou wish.

jimbo45 · Dec 9, 2021

Hi there
I simply use Virtual (vhdx) files (no not a VM but "physical vhdx files" ) and then can have as many Windows / Linux installations as I want on a physical HDD -- whether internal / external device. All the windows files are just vhdx files (non GPT) on a standard ntfs formatted HDD with 1 single EFI partition and a 128 MSR partition.

So each device has 1 single EFI file / partition no matter how many Windows systems are on it.

No prob whatsoever - maintenance is a doddle as anything you do on 1 Windows system doesn't touch the others.

The only drawback is that if you want to upgrade to a completely new build then you will have to import the vhdx file into hyper-V and upgrade from within HYPER-V . Otherwise new install required. Cumulative updates via WU work OK though. I wouldn't ever go back to not using vhdx files for windows now.

No need to disconnect any drives -- however many Windows systems you have !!!!No need either for any 3rd party tools for managing boot loader etc -- std Windows commands only for Windos and install media for Linux.

Cheers
jimbo

obelix · Dec 9, 2021

This is not well set up, so in the bios the boot disk only boots the first disk that is found in the windows boot manager in the bios the second disk has no boot because it is written to the healthy partition and sometimes the bios ignores it and you will have problems later.
I have a lot of experience with that

obelix · Dec 9, 2021

Once upon a time when there were windows on MBR partition I had 4 operating systems on one disk now it's different and now you can install windows 11 in MBR partition.

steve17 · Dec 9, 2021

Another thing to keep in mind is "fast startup". It seems that with multiple Win10 and/or Win11, you need to disable fast startup, or disable hibernate. Otherwise I get Windows "repairing" various partitions at startup.

TheMystic · Dec 11, 2021

steve17 said:
That didn't work for me. So you have an EFI/System partition on multiple disks?

View attachment 15635

You just need one EFI partition, irrespective of how many bootable Disks and bootable partitions you have on your system.

All you need to do is map the OS partitions to the EFI partition with a single command for each OS. Assuming you have the OS installed in 5 different Disks or Partitions C, D, E, F & G, and let's say you assign the letter Z to the EFI partition using Diskpart. The following are the commands you need to pass:

bcdboot C:\Windows /s Z:
bcdboot D:\Windows /s Z:
bcdboot E:\Windows /s Z:
bcdboot F:\Windows /s Z:
bcdboot G:\Windows /s Z:

and so on...

You don't need a separate EFI partition for each disk or each bootable partition.

The above commands essentially tell the system where each OS is installed and where to boot from when you make a choice. The EFI partition contains the address of each OS, and points the system to the right OS based on user input.

Please do note that the Disk with the EFI partition must be always available if you set it up this way.

If EFI partition goes corrupt, it is extremely simple to erase the partition and map the OSes again. Check this post.

No need for 3rd party apps.