Cloned SSD does not boot

[TechnoMax]

I was unable to boot a restored Windows backup. So I reinstalled Windows and installed the necessary programs. Then I wanted to switch from this working 1TB SSD to a better, faster, and larger SSD, so I cloned the Windows SSD to another NVMe drive. However, the clone cannot be booted, even when I choose them in the boot drive selector at start up.
I then resorted to my usual helper for boot problems, a USB boot stick with Macrium Reflect. However, it couldn't restore the boot files either because it couldn't find an active partition on the larger SSD (“can be any primary partition on the boot drive”). But how can I fix this on a UEFI computer with GPT drives?

 

[TechnoMax]

Another forum gave my a ChatBot AI answer that was a step-by-step tutorial that worked.
The problem were the Boot Configuration Date. On UEFI-based systems, it resides in the \EFI\Microsoft\Boot\BCD file on the EFI System Partition (ESP). The solution was:

Recreate the boot files with bcdboot
Find which letter Windows is on in the rescue environment:

• Try DIR C:\Windows, D:\Windows, etc., or run diskpart list vol to see which volume is the Windows partition and note its letter (assign a letter if it has none).

Then run (replace letters as needed):
bcdboot C:\Windows /s S: /f UEFI

You have to boot from another drive, in my case from a bootable external Windows copy on an USB SSD. Give the EFI Partition a drive letter (in the example S, C: must be replaced by the drive letter of the Windows system partition that you want to make bootable again.