Dual boot (Win 10 and Win 11) doesn't work

The PC already had Win 11 on it.
I added a new SSD and installed Win 10 on the new SSD via a USB stick.
Of course dual boot now doesn't work.
It shows a menu with Win 11 and Win 10, it boots fine into Win 11 but not into Win 10.
If I try Win 10 it resets the PC and reboots.
I tried Macrium Reflect off a USB to repair the BCD but it made no change.
Now what?

For me I used EasyBCD and just add the drive to the list

Same here

!@#$%^&*( EasyBCD.
It completely nuked the BCD and the PC was unbootable.
Luckily Macrium could save it back so I can get into Win 11 again.
I tried the EasyBCD Recovery disk on a USB and that one was halted by the BIOS as it behaved like a virus. I mean???

For some reason the dear Windows installers have ensured I have 4 EFI partitions. 2 on the brand new SSD. I mean WTF??
I love this clown level software quality.

post a screenshot of diskmgmt window

Here you go!






Sorry for venting, wasting this much time does not make me happy.

open admin cmd prompt and type:

bcdboot e:\windows /addlast

SIW2 said:

open admin cmd prompt and type:

bcdboot e:\windows /addlast

Click to expand...

That worked! What does it do? I mean I read the description but ...
And how did you figure what was missing? I tried to find some data to look at to see what was wrong but ...

Sineira said:

That worked! What does it do? I mean I read the description but ...
And how did you figure what was missing? I tried to find some data to look at to see what was wrong but ...

Click to expand...

It's called knowledge gained from many years of experience dealing with similar issues - or even just practicing commands when there is no issue. A lot of us "old school" users prefer to use the basic commands instead of relying upon third party programs that are not much more that GUI's for the commands that we know how to use.