I am trying to create UEFI bootable USB sticks of Windows 8. What I do is the following:

select disk 1
convert gpt
create partition primary
format quick fs=ntfs

I then just dump the contents of the ISO into the USB. It does not boot but when I format to fat32 it works. Is this normal, or is it just my laptop that's not able to locate NTFS UEFI partitions?

FAT32 is really old and will essentially limit OS image sizes to 4GB (the WIM can't be bigger than that in a fat32 system).

I tried doing "create partition efi" to create a EFI system partition but I was unable to access it. Could I theoretically create an EFI system partition in linux, dump the contents of /efi/ into it, then create a primary NTFS partition and dump the rest of the stuff onto that partition?

This isn't a question pertaining to an issue since I solved it (formatting to fat32). I just want to know what's going on.

EDIT: Also as a bonus question. All the blogs and articles relating to "Create Windows 8 Bootable USB" do not mention "convert gpt" and just say to dump the contents of the ISO onto the disk. Some say to run bootsect.exe, others don't (doesn't make sense since UEFI doesn't use boot sectors). I don't see how this would work since UEFI needs a GPT disk to boot from. Is my laptop just very strict while others are lax on the standard?

  • Your theory that your laptop is strict has not weight a UEFI system is a UEFI system ( it has a standard ). – Ramhound Oct 23 '13 at 22:41
  • yeah, a lot of things are "standardized" but some things obey them more than others. Hence the reason why you have to tweak your code to work on firefox, chrome, and ie even though HTML\CSS is supposedly standardized. – UEFIGUY33 Oct 23 '13 at 22:46
  • I will just say your browser comparison is entirely different. There are not UEFI extensions, there are browser extensions, and you don't HAVE to use extensions. – Ramhound Oct 23 '13 at 22:48
  • 2
    Although EFI is standardized, and has 3,000 pages documenting just the basics of it, there are infuriating differences between the implementations. For instance, many EFIs are quite happy to boot from MBR disks or from non-ESP FAT partitions, but some seem to have problems with that. Others have bugs that cause certain boot loaders to fail. Secure Boot is an option that, if enabled, will cause certain OSes to not boot. Note also that "EFI" stands for "Extensible Firmware Interface." There definitely are EFI extensions! – Rod Smith Oct 24 '13 at 18:34
  • Some motherboards' UEFI firmware can read NTFS, and can boot directly from the /EFI/BOOT folder on an NTFS partition. I have only seen high end motherboards such as the Asus Maximus / Rampage / Deluxe series support this. Most motherboards will only UEFI boot from a FAT partition. – Monstieur Nov 21 '16 at 2:40

On a normal hard disk installation of most any EFI-based OS, you'll have, at a minimum, one FAT EFI System Partition (ESP) and one partition for the OS itself. The ESP holds a boot loader for the OS, possibly along with files to support the boot loader (fonts, configuration files, drivers, etc.), and possibly even the OS's kernel. The OS partition holds more-or-less the same OS files you'd find on a BIOS-based installation of the same OS. Depending on the OS, you might have additional partitions, too -- data partitions, a swap partition, etc.

There can be exceptions to this rule, particularly for installation media or emergency disks. For instance, you could put the whole OS in the ESP. Also, most EFIs are happy to boot from partitions that are not ESPs, so you could just have one big non-ESP FAT partition, as you've got. This can work fine for an emergency disk, but I wouldn't recommend setting up a regular OS installation in this way; I'd use a separate ESP and OS partition.

Note that a standard EFI can read FAT, but cannot read NTFS, ext2/3/4fs, HFS+, or any other filesystem. (Apple's EFI can read HFS+, and so can read its boot loader from a Mac OS X root partition rather than from the ESP, but Apple's EFI is the exception rather than the rule. A few EFIs also have ISO-9660 filesystem drivers -- but again, they're exceptions to the rule.) Because FAT is the only filesystem that's guaranteed to be readable by EFI, an attempt to build a boot disk that does not include a FAT partition is doomed to failure, except of course when used on those unusual EFIs that support additional filesystems.

I can't provide a procedure to set up a Windows emergency disk to use separate EFI and Windows partitions, since I'm more of a Linux person than a Windows person. Unless you run into a specific problem with your approach, though, I'd just stick with it; at least you know it works.

  • A real need for a separate FAT EFI partition and the main NTFS OS installation partition arises when the OS installation distribution contains large files. (I assume install.wim larger than 2GB can't be put on FAT.) (That's how I came to this question.) So far, I don't understand how to make it work, because if only /efi/ (and /boot/) are copied to FAT, it fails to proceed loading the installer... – imz -- Ivan Zakharyaschev Jun 30 '16 at 12:14
  • There are EFI filesystem drivers available for non-FAT filesystems, including HFS+, NTFS, ISO-9660, and several Linux filesystems. Some of these come with my rEFInd boot manager, and others are available in the efifs collection, which is based on GRUB's drivers. You can use rEFInd or an EFI shell binary with a startup script to load whatever driver(s) you need, then load the big files off the now-accessible filesystem. A custom boot loader to do this could be written if that's all you need. – Rod Smith Jun 30 '16 at 20:37

use rufus (search for the latest version on google). select the iso image.Go to the second option bar from the top and select the "gtp for uefi filesystems" and burn your iso to a usb thumbdrive (has to be at least 4 gigs in size). Boot from your usb and cross your fingers. If it doesnt work then ...too bad

  • This is really not helpful. It describes the process the OP has already attempted. – Burgi Mar 23 '16 at 10:36
  • 2
    @Burgi - I don't think so. Rufus does include UEFI:NTFS which enables booting NTFS partitions from UEFI. I don't believe OP has been writing anything that resembles UEFI:NTFS with their manual process, which Rufus will automatically do if it detects a >4GB file. – Akeo Mar 30 '16 at 0:14
  • @pbatard My comment was designed to prompt the poster to edit their answer to clarify how their answer differs from what the OP has already tried. – Burgi Mar 30 '16 at 10:29

I recommend using WinToUSB to create Windows installation USB flash dirve, WinToUSB has released a new feature called "Windows Installation USB Creator" which allows you to create a Windows installation USB falsh drive with a few simple steps, with this feature you can create a Windows installation USB flash drive to install Windows 10/8/7 on both BIOS and UEFI computers.

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