Windows 10 (ssd1) won't boot as default after installation Windows 11 (ssd2)

Question

My laptop contained one m.2 SSD with an installation of Windows 10 Pro (disk 1). I installed a second m.2 SSD on which I installed Windows 11 Pro (disk 0). When I turn on the laptop I see the boot manager. Win11 starts by default. I would like to change that to default Win10. If I adjust the order (so that Win10 starts after x seconds by default), a black screen appears after the boot manager. Nothing else happens (not even after 10 minutes). I can still get into Win10 in the following situations:

Option 1:

• set Win10 as default
• start Win11 via boot manager
• in Win11 I choose shutdown
• turn on laptop
• start Win10 via boot manager
• Windows 10 starts up

Option 2:

• set Win11 as default
• start Win10 via boot manager

Both options are not ideal, because I want to boot Win10 by default (without having to choose anything). It looks like something is going wrong in the boot manager.

I would like to know what other options I can try. Thanks for the help!

Answer 1

Boot into Windows 11 from the boot manager

Open Command Prompt as Admin and backup the BCD.

bcdedit /export C:\BCD_Backup

Now rebuild BCD:

bootrec /fixmbr

bootrec /fixboot

bootrec /scanos

bootrec /rebuildbcd

Open Windows 11 from the boot manager.

Open Command Prompt as Admin and list boot entries:

bcdedit /enum

Look for the entry that corresponds to your Windows 10 installation. Note the identifier (usually in the form of {xxxx-xxxx-xxxx-xxxx}).

Type the following command, replacing {identifier} with the actual identifier of the Windows 10 entry:

bcdedit /default {identifier}

bcdedit /timeout 5

Restart your laptop to see if Windows 10 boots by default.

Answer 2

Hello,

Changing the boot priority in the BIOS/UEFI settings.

1. Restart your computer and press the appropriate key (typically F12, DEL, ESC) to enter into your BIOS/UEFI settings. The key might vary depending on your laptop’s manufacturer—refer to your user manual if needed.
2. Go to the ‘Boot’ option/tab.
3. Change the boot priority so the SSD containing Windows 10 is at the top.
4. Save the changes and exit. The computer will then restart.

Best Regards,

Hania Lian

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