That way, you will need to disable Secure Boot in the UEFI firmware to boot into the media. Rufus uses a single FAT32 partition when the biggest file is under or equal to 4GB otherwise, you will only have NTFS as an option with UEFI + GPT.SLaks way will be possible only as long as the biggest file (normally install.wim) is lesser or equal to 4GB because it uses single FAT32 partition on the boot drive.So, the Isos, which are having files ( extracted ) larger than 4GB, has to be applied to the boot media with some tricks. But FAT32 can only support files that are less than or equal to 4GB. Normally, UEFI boot needs a FAT32 format drive or such partition on the boot drive.With customized ISOs, it will always be experimental and may support one or the other.Most UEFI systems will be able to boot only 圆4 boot media in UEFI mode as here.