7 ms·

Somewhat related… for a while now Microsoft have provided publicly downloadable iso images for Windows 10 that you can’t image to a usb drive without needing sp

Somewhat related… for a while now Microsoft have provided publicly downloadable iso images for Windows 10 that you can’t image to a usb drive without needing special EFI NTFS software from a third party which in turn requires disabling secure boot (as it’s not secure boot signed) Why you may ask? Simply because the iso contains a file larger than 4GB (install.wim) so you cannot use a FAT32 formatted usb drive (FAT32 is needed for EFI boot). Instead tools like Rufus provide their own EFI NTFS boot loader. Interestingly Microsoft’s own usb creator doesn’t include install.wim but instead install.esd which is less than 4GB so can use FAT32. I have no idea why the iso uses a wim file whereas the windows usb creator uses an esd file. I do know the esd version is a little slower to install (only a minute or two). I guess because of higher compression. This is a pain because making a Windows bootable installer on Linux or macOS is now more complicated than it need be as you cannot simply put the iso onto the usb drive with dd or gdisk as you would normally do. Does anyone know why this is the case? As a workaround you can use Microsoft’s usb media creator to build an iso with the esd file then use dd as usual. But of course this requires a Windows system to run the Windows only usb creation tool and is a slower process than just downloading an iso directly. Annoying.

deleted 5y ago
[deleted]
MarkSweep 5y ago
EDIT: I just realized no of the bellow helps you if you are not on Windows =( The documented way to work around the 4GB limitation is to use the dism.exe /Split-Image command. This will turn the one large .wim file into multiple smaller files. https://docs.microsoft.com/windows-hardware/manufacture/desktop/split-a-windows-image--wim--file-to-span-across-multiple-dvds https://docs.microsoft.com/windows-hardware/manufacture/desk... I ran into this when I was working on SimpleDiskImager. It is my disk image writer that tries to find a balance between dd's literal-minded copying of bytes (which does not correctly handle GPT partitioning) and the opinionated and invasive modifications that Rufus makes (not yet compatible with secure boot). I have not yet integrated support for writing Windows installer ISOs yet, but you can see the start of it in the ConvertEfiIsoToFat directory. https://github.com/AustinWise/SimpleDiskImager https://github.com/AustinWise/SimpleDiskImager
tw04 5y ago
Have you tried ventoy? It’s worked with everything I’ve thrown at it. https://github.com/ventoy/Ventoy https://github.com/ventoy/Ventoy
- howdydoo 5y ago
  Thanks for posting this. I'm about to build a PC and you just saved me from having to buy a second usb stick just for booting an OS installer
- nsonha 5y ago
  except MacOS, I know it's illegal but if only...
  - InvaderFizz 5y ago
    I've been using an IODD for years, works on Macs too. I have every macOS release back to 10.6 as a bootable iso.
  - toyg 5y ago
    A breach of licensing contracts is not "illegal".
zamadatix 5y ago
On Linux look at wimsplit which will convert the .wim into a series of .swm of smaller size. As for why my guess is the .iso came from the standard distribution image used in CDs and handed to OEMs and whatnot. ESD doesn't allow direct image modification/slipstreaming and the official DVDs don't care if the file is >4GB as long as it fits on a disc. The Windows USB tool actually creates an ISO based on the current update files on the Windows Update servers (for the major distribution, I don't think it includes minor updates), it's not pulling down a precompiled .iso. You'll actually get a different hash whenever you make this ISO as a result. Similarly if you dump to a USB drive it's just pulling the files to put there not extracting a .iso containing an .esd. As to why they haven't implemented a better way for Linux/Mac users without access to a Windows machine to create a bootable Windows USB? It probably isn't a common enough problem for them to care.
withinrafael 5y ago
Modern PCs made in the last 5+ years or so come with EFI drivers to read NTFS partitions. FAT32 is not "needed for EFI boot". You can extract the ISO (e.g. with 7z) onto a USB stick and you're done in most cases.
- zamadatix 5y ago
  The spec allows it but whether FAT32 needed depends solely on the board not the age. I've got plenty of recent boards that don't take NTFS/exFAT - I usually find out when I'm scratching my head as to why it doesn't show up in the boot menu.
- satysin 5y ago
  Some systems do indeed come with NTFS EFI support. However it isn’t a common thing. For example the new Microsoft Surface Studio Laptop I was using a few weeks ago does not support NTFS and the support documentation gives you instructions to create a FAT32 partition. This is why it’s fresh in my mind. Not a big deal, just annoying.
- satysin 5y ago
  Out of interest I did a little test this afternoon. Got a 128GB SanDisk USB flash drive. Used diskpart to clean the disk then created a single NTFS GPT partition. Extracted the current Windows 11 ISO they offer for download onto the drive using 7-Zip. Tried to boot on a Surface Studio Laptop, a Lenovo ThinkPad X1 Carbon from 2019 and an Alienware M15 from this year. Failed on all three. Just to be on safe side I used bootsect to ensure the USB is bootable but again failed to boot on all three. I then used the MS Media Creation Tool which happily creates a FAT32 formatted USB drive. This naturally boots fine on all systems. So while technically me saying FAT32 is needed for EFI is not correct the reality is FAT32 is what you can be [almost?] certain is supported on any system using EFI. Not even on Microsoft's brand new flagship laptop or a brand new, high end gaming laptop from Dell appear to have NTFS support in their EFI. I wish it were as simple as just extract the iso to an NTFS USB drive and boot.
  - withinrafael 5y ago
GekkePrutser 5y ago
Yeah I noticed this. I tried using DD to 'burn' the windows 11 ISO to a USB stick and it didn't work. I had to use Rufus as per MS' instructions. It's very weird to me that they include a third-party app in this workflow.
- Fnoord 5y ago
  It Just Works (tm) with Ventoy.
Tsiklon 5y ago
I've had success with using exFAT on my Mac for installing Windows, but I think that support for this in EFI on most hardware may be even less common than NTFS support in EFI. Using DD for windows images has been a pain for years, even before windows 10, manually copying the image content with rsync to a correctly formatted external drive for me was the most reliable way in the Win8.1 era.
swiley 5y ago
>Installing Windows on actual hardware and not just running a VM with virGL.

deleted 5y ago

[deleted]

MarkSweep 5y ago

EDIT: I just realized no of the bellow helps you if you are not on Windows =( The documented way to work around the 4GB limitation is to use the dism.exe /Split-Image command. This will turn the one large .wim file into multiple smaller files. https://docs.microsoft.com/windows-hardware/manufacture/desktop/split-a-windows-image--wim--file-to-span-across-multiple-dvds https://docs.microsoft.com/windows-hardware/manufacture/desk... I ran into this when I was working on SimpleDiskImager. It is my disk image writer that tries to find a balance between dd's literal-minded copying of bytes (which does not correctly handle GPT partitioning) and the opinionated and invasive modifications that Rufus makes (not yet compatible with secure boot). I have not yet integrated support for writing Windows installer ISOs yet, but you can see the start of it in the ConvertEfiIsoToFat directory. https://github.com/AustinWise/SimpleDiskImager https://github.com/AustinWise/SimpleDiskImager

tw04 5y ago

Have you tried ventoy? It’s worked with everything I’ve thrown at it. https://github.com/ventoy/Ventoy https://github.com/ventoy/Ventoy

howdydoo 5y ago
Thanks for posting this. I'm about to build a PC and you just saved me from having to buy a second usb stick just for booting an OS installer
nsonha 5y ago
except MacOS, I know it's illegal but if only...
- InvaderFizz 5y ago
  I've been using an IODD for years, works on Macs too. I have every macOS release back to 10.6 as a bootable iso.
- toyg 5y ago
  A breach of licensing contracts is not "illegal".

zamadatix 5y ago

On Linux look at wimsplit which will convert the .wim into a series of .swm of smaller size. As for why my guess is the .iso came from the standard distribution image used in CDs and handed to OEMs and whatnot. ESD doesn't allow direct image modification/slipstreaming and the official DVDs don't care if the file is >4GB as long as it fits on a disc. The Windows USB tool actually creates an ISO based on the current update files on the Windows Update servers (for the major distribution, I don't think it includes minor updates), it's not pulling down a precompiled .iso. You'll actually get a different hash whenever you make this ISO as a result. Similarly if you dump to a USB drive it's just pulling the files to put there not extracting a .iso containing an .esd. As to why they haven't implemented a better way for Linux/Mac users without access to a Windows machine to create a bootable Windows USB? It probably isn't a common enough problem for them to care.

withinrafael 5y ago

Modern PCs made in the last 5+ years or so come with EFI drivers to read NTFS partitions. FAT32 is not "needed for EFI boot". You can extract the ISO (e.g. with 7z) onto a USB stick and you're done in most cases.

zamadatix 5y ago
The spec allows it but whether FAT32 needed depends solely on the board not the age. I've got plenty of recent boards that don't take NTFS/exFAT - I usually find out when I'm scratching my head as to why it doesn't show up in the boot menu.
satysin 5y ago
Some systems do indeed come with NTFS EFI support. However it isn’t a common thing. For example the new Microsoft Surface Studio Laptop I was using a few weeks ago does not support NTFS and the support documentation gives you instructions to create a FAT32 partition. This is why it’s fresh in my mind. Not a big deal, just annoying.
satysin 5y ago
Out of interest I did a little test this afternoon. Got a 128GB SanDisk USB flash drive. Used diskpart to clean the disk then created a single NTFS GPT partition. Extracted the current Windows 11 ISO they offer for download onto the drive using 7-Zip. Tried to boot on a Surface Studio Laptop, a Lenovo ThinkPad X1 Carbon from 2019 and an Alienware M15 from this year. Failed on all three. Just to be on safe side I used bootsect to ensure the USB is bootable but again failed to boot on all three. I then used the MS Media Creation Tool which happily creates a FAT32 formatted USB drive. This naturally boots fine on all systems. So while technically me saying FAT32 is needed for EFI is not correct the reality is FAT32 is what you can be [almost?] certain is supported on any system using EFI. Not even on Microsoft's brand new flagship laptop or a brand new, high end gaming laptop from Dell appear to have NTFS support in their EFI. I wish it were as simple as just extract the iso to an NTFS USB drive and boot.
- withinrafael 5y ago

GekkePrutser 5y ago

Yeah I noticed this. I tried using DD to 'burn' the windows 11 ISO to a USB stick and it didn't work. I had to use Rufus as per MS' instructions. It's very weird to me that they include a third-party app in this workflow.

Fnoord 5y ago
It Just Works (tm) with Ventoy.

Tsiklon 5y ago

I've had success with using exFAT on my Mac for installing Windows, but I think that support for this in EFI on most hardware may be even less common than NTFS support in EFI. Using DD for windows images has been a pain for years, even before windows 10, manually copying the image content with rsync to a correctly formatted external drive for me was the most reliable way in the Win8.1 era.

swiley 5y ago

>Installing Windows on actual hardware and not just running a VM with virGL.