@RUSerious you are right there is a problem with the file extention, I'll fix this later. @Atari800XL Problem is Microsoft lately produce dirty images that contain boot files. files like the following should not be in the image, but create with setup on the boot partition. \boot\ \efi\ \bootmgr \bootnxt this time there was even an empty bcd store, but bcdboot is designed to extend an existing or create a new one. It can not handle an empty one. An yes please mention these issue, whenever you find them.