Windows 10: How to set preferred Windows Boot Manager in UEFI setup for Dual Drive/Dual Boot

I have a new machine with M.2 drive and pre-installation of Windows 11 Lenovo ThinkCentre M90q. I've added an SSD to the SATA bus and installed Windows 10 there. I want both drives to boot Windows successfully independent of the other. When I installed Windows 10 on the SSD, the Windows installer would not create the UEFI partition or the Windows Recovery partition with both drives present. You can read about it here. I needed to remove the M.2 pre-installation of Windows 11, to achieve a complete installation of Windows 10 on the SSD. With both drives back in the machine, the boot process d

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Dual Booting

Please follow the steps in the tutorial for how to post the screenshot. I cannot even see Disk 0, 1 and 2 on the drive map, and the columns were not spread so i can see the labels in the listings above even though it lllustates how to do this.

As long as you don't have a UEFI install then you can move the boot loader to Windows 10 so that it manages the Dual Boot using it's menu, add the Dual Boot back from there. These same steps using EasyBCD should do it:

http://www.sevenforums.com/tutorials/209885-boo...

 

Dual Booting 2 Windows Systems Using UEFI Boot Manager

This was an option until you deleted the EFI System Partition on Disk 2. UEFI Dual Boot means switching between Windows Boot Managers, requiring an EFI System Partition each.

But you can still do Windows Dual Boot. Execute

bcdboot E:\Windows

to add "Windows Disk 2" to the Disk 1 boot manager (EFI System Partition).

 

Dual Booting 2 Windows Systems Using UEFI Boot Manager

Hi Volume Z,

Well your Microsoft colleague Ramesh said the having another EFI partition on Disk 2 was going to cause problems and he seemed to be casting doubt about the viability of any dual boot solution, see his posts earlier in this thread. However I am reluctant to give up on that objective. I find it hard to believe it isn’t possible as other people are clearly doing it.



From your latest post you clearly think it is still viable. I was struck by the distinction that you seem to be making, which if I understand you correctly is:-

a) “Windows Dual Booting” involves putting two entries in the BCD on Disk 1 and using a boot menu.

b) “UEFI Dual Booting” involves having an EFI partition on each disk and using the UEFI Boot Menu to choose what to boot.



If I execute the “bcdboot E:\Windows” command as you suggest I’m guessing that this will add a second entry to the Disk 1 BCD in the Disk 1 EFI. Will this cause the windows boot manager menu to appear on boot to select which system to start ?. If so that’s a good start, at least I have two separate bootable systems. This seems like a relatively low risk step and I am actively considering it. I would appreciate any further clarification you can give of the effect of the bcdboot command that you have suggested that I execute.



As for going further and having an EFI partition on each disk and using the UEFI BIOS Boot Manager as the menu, that was my original objective. But I confess I am now concerned about any problems it might cause. If I can get Windows Dual Booting working I will be content with that.



Thanks



Bob