Because I want to use a new hard drive, I copied windows like described in https://wiki.archlinux.org/index.php/disk_cloning with
dd if=/dev/sdb2 of=/dev/sda1 status=progress. The partition of windows (7) now seems to be working fine, I can open it, view files, and so on.
With my normal ubuntu, I afterwards ran
sudo update-grub and windows was found like normaly. Unfortunately, if I choose windows in the grub menu, it gets stuck at showing an underscore and does not boot.
Is there any way of debugging this issue? Since Windows seems to do nothing, I do not get any logs or hints, what I could do with the partition.
You have to fix Windows 7 boot, so it can boot from its “new” disk by itself.
Fix MBR and partition boot record using bootsect.exe
Fix BCD using bcdboot.exe
Alternatively use bootrec.exe from recovery environment.
Note: GRUB can chainload Windows only if Windows can boot by itself.
How to start windows 10 after restored or cloned with dd on ubuntu?
Issue: reboot loop
Solution was: F8 key troubleshoot startup option then more options at the bottom. Microsoft was cheeky to hid this here 🙂
Use SAFE MODE for the first start after dd and you will be the star.