- Create an installation media
- Boot PC with an installation media
- Press SHFIT + F10 on the first screen to bring up Command Prompt
- Run the following commands and click Enter each time at Command Prompt:
diskpart
list disk
select disk N (N refers to the disk which contains the deleted the EFI System partition)
list partition
create partition efi
format quick fs=fat32
list partition
list volume (find the volume letter which belongs to the installed Windows OS)
select volume N (select system partition)
assign letter=K
exit (exit diskpart, or open another command prompt)
bcdboot M:\windows /s K: /f UEFI (M refers to the volume letter of installed Windows OS)
(bcdboot m:\windows command will copy the boot files from Windows partition to the EFI system partition and create BCD store in the partition)
Next remove installation drive and restart your computer