Creating EFI System Partition for Windows

gistfile1.txt

- Boot the computer using the Windows 7/8/8.1/10 installation media.
- On the first screen, press Shift+F10 to bring up the command prompt.
- Run the following commands at the command prompt.

diskpart
list disk
select disk # Note: select the disk where you want to add the EFI System partition.
list partition
select partition # Note: select the Windows OS partition (# number) or your data partition.
shrink desired=100
create partition efi size=100
format quick fs=fat32
assign letter=s
list partition
list volume # Note: check the volume letter where the Windows OS is installed.
exit

bcdboot X:\windows /s S:
Note: Replace "X" with the volume letter of the Windows OS partition.

BCDBoot copies the boot files from the Windows partition to the EFI System partition and creates the BCD store in the same partition.
Remove the Windows installation media and restart the computer into your BIOS settings and set the SSD as the First Boot Device.

Found in: https://www.tenforums.com/installation-setup/52837-moving-recreating-efi-partition.html#post698505