I believe I use windows 11 media creation tool to create the install for my new PC. How much storage space would my USB flash drive need to store the install data?
Videos
This answer is summarized below.
- MBR partition a 16 GB or larger flash drive to contain a FAT32 volume and an ExFAT volume.
- Copy all the files, except
sources/install.wim, from the mounted Windows ISO file to the FAT32 volume on the flash drive. - Copy
sources/install.wimfrom the mounted Windows ISO file to the ExFAT volume on the flash drive. - Boot from the flash drive and enter a command to split the
install.wimon the ExFAT volume to two files placed on theFAT32volume. - The result is an USB flash drive which can be used to install Windows 11.
The steps are given next.
Goto Microsoft's Download Windows 11 website and download the Windows 11 disk image (ISO) for x64 devices. In my case, the
Win11_24H2_English_x64.isofile was downloaded to myDownloadsfolder. If your file name is different, then make the appropriate substitutions when entering the commands below.Insert a 16 GB or larger flash drive in an USB port on or connected to the Mac.
Open a Terminal application window.
Use the command below to determine the identifier for the USB flash drive. I my case, this was
disk2. If your identifier is different, the make the appropriate substitutions in the following commands.diskutil list externalEnter the command below to format the flash drive.
diskutil partitiondisk disk2 mbr fat32 MYFAT32 8G exfat MyExFAT REnter the command below to remove all extended attributes from the Windows ISO file. This will remove the quarantine placed on the file when it was downloaded.
xattr -c ~/Downloads/Win11_24H2_English_x64.isoEnter the command below to mount the Windows 11 ISO file. In my case, the output from the command shows the file was mounted on
/Volumes/CCCOMA_X64FRE_EN-US_DV9. If your folder name is different, then make the appropriate substitutions when entering the commands below.hdiutil attach ~/Downloads/Win11_24H2_English_x64.isoEnter the command below to change the current directory to
/Volumes/CCCOMA_X64FRE_EN-US_DV9.cd /Volumes/CCCOMA_X64FRE_EN-US_DV9Enter the commands below to copy the files from the mounted ISO to the flash drive. Note: Since the
install.wimfile is very large, thecpcommand can take a while to complete.rsync -r -t --exclude=sources/install.wim . /Volumes/MYFAT32 cp sources/install.wim /Volumes/MyExFATEnter the commands below to unmount the Windows 11 ISO file.
cd ~ hdiutil detach /Volumes/CCCOMA_X64FRE_EN-US_DV9Enter the command below to eject the flash drive. Afterwards, you can remove the flash drive.
diskutil eject disk2You can quit the Terminal application.
Using the computer where Windows is to be installed, UEFI boot from the flash drive. You should get a window similar to the one shown below. You can ignore the contents of this window.
Press the shift+F10 key combination to open Command Prompt window.
Enter the command below. From the output, determine the drive letters for the
MYFAT32andMyExFATvolumes. In my case, the wasCandDrespectively. If your letters are different, the make the appropriate substitutions forc:\andd:\when entering thedismcommand given below.echo list volume | diskpartEnter the command below to create the
install.swmandinstall2.swmfiles in thec:\sourcesfolder. Note: This command will take a while to complete.dism /split-image /imagefile:d:\install.wim /swmfile:c:\sources\install.swm /filesize:4000Enter the command below to close the Command Prompt window.
exitClose the window. When the popup shown below appears, select "Yes". The computer will reboot.
The next time you UEFI boot from this USB flash drive, you should encounter the following window. You then can proceed and install Windows 11.
Example of Using the Terminal Window
Last login: Sun Mar 9 09:16:57 on console
davidanderson@Davids-Mac ~ % diskutil list external
/dev/disk2 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: FDisk_partition_scheme *15.9 GB disk2
1: DOS_FAT_32 MYFLASHDRV 15.9 GB disk2s1
davidanderson@Davids-Mac ~ % diskutil partitiondisk disk2 mbr fat32 MYFAT32 8G exfat MyExFAT R
Started partitioning on disk2
Unmounting disk
Creating the partition map
Waiting for partitions to activate
Formatting disk2s1 as MS-DOS (FAT32) with name MYFAT32
512 bytes per physical sector
/dev/rdisk2s1: 15594504 sectors in 1949313 FAT32 clusters (4096 bytes/cluster)
bps=512 spc=8 res=32 nft=2 mid=0xf8 spt=32 hds=255 hid=2048 drv=0x80 bsec=15625000 bspf=15230 rdcl=2 infs=1 bkbs=6
Mounting disk
Formatting disk2s2 as ExFAT with name MyExFAT
Volume name : MyExFAT
Partition offset : 15628288 sectors (8001683456 bytes)
Volume size : 15370240 sectors (7869562880 bytes)
Bytes per sector : 512
Bytes per cluster: 32768
FAT offset : 2048 sectors (1048576 bytes)
# FAT sectors : 2048
Number of FATs : 1
Cluster offset : 4096 sectors (2097152 bytes)
# Clusters : 240096
Volume Serial # : 67cdc143
Bitmap start : 2
Bitmap file size : 30012
Upcase start : 3
Upcase file size : 5836
Root start : 4
Mounting disk
Finished partitioning on disk2
davidanderson@Davids-Mac ~ % xattr -c ~/Downloads/Win11_24H2_English_x64.iso
davidanderson@Davids-Mac ~ % hdiutil attach ~/Downloads/Win11_24H2_English_x64.iso
/dev/disk3 /Volumes/CCCOMA_X64FRE_EN-US_DV9
davidanderson@Davids-Mac ~ % cd /Volumes/CCCOMA_X64FRE_EN-US_DV9
davidanderson@Davids-Mac CCCOMA_X64FRE_EN-US_DV9 % rsync -r -t --exclude=sources/install.wim . /Volumes/MYFAT32
davidanderson@Davids-Mac CCCOMA_X64FRE_EN-US_DV9 % cp sources/install.wim /Volumes/MyExFAT
davidanderson@Davids-Mac CCCOMA_X64FRE_EN-US_DV9 % cd ~
davidanderson@Davids-Mac ~ % hdiutil detach /Volumes/CCCOMA_X64FRE_EN-US_DV9
"disk3" ejected.
davidanderson@Davids-Mac ~ % diskutil eject disk2
Disk disk2 ejected
davidanderson@Davids-Mac ~ %
Example of Using the Command Prompt Window
Microsoft Windows [Version 10.0.26100.1742]
(c) Microsoft Corporation. All rights reserved.
X:\sources>echo list volume | diskpart
Microsoft DiskPart version 10.0.26100.1150
Copyright (C) Microsoft Corporation.
On computer: MININT-NBNQP5I
DISKPART>
Volume ### Ltr Label Fs Type Size Status Info
---------- --- ----------- ----- ---------- ------- --------- --------
Volume 0 E DVD-ROM 0 B No Media
Volume 1 C MYFAT32 FAT32 Removable 7629 MB Healthy
Volume 2 D MyExFAT exFAT Removable 7505 MB Healthy
DISKPART>
X:\sources>dism /split-image /imagefile:d:\install.wim /swmfile:c:\sources\install.swm /filesize=4000
Deployment Image Servicing and Management tool
Version: 10.0.26100.1150
The operation completed successfully.
X:\sources>exit
User Dan Is Fiddling By Firelight posted the following comment.
I'm leaving this as a comment since without access to a Mac I don't feel I could write a complete answer. Instead of directly creating a bootable windows installer USB, create a Ventoy bootable USB. Once you do that you can copy bootable drive images in all the major formats on as ordinary files, and then start them from a basic menu system that Ventoy shows when it boots. It's slightly more work the first time, but as long as you don't reformat the USB it'll make any future uses much easier since it reduces the operation to a simple copy/paste. ventoy.net/en/index.html
I decided to post this answer in response to the above comment. Note that the question does not explicitly rule out posting a solution which uses third party tools.
This answer is summarized below.
- Download Ventoy live CD image (ISO) file, then copy this file to an 8 GB or larger flash drive.
- Boot from the flash drive and install Ventoy to the same flash drive.
- Download the Windows 11 ISO file and copy to the flash drive.
- Boot from the flash drive and install Windows 11. If necessary, first enroll the key in MOK manager.
The steps are given next.
Goto SourceForge's Ventoy project files website and download the Ventoy live CD image (ISO) for x64 devices. In my case, the
ventoy-1.1.05-livecd.isofile was downloaded to myDownloadsfolder. If your file name is different, then make the appropriate substitutions when entering the commands below.Insert an 8 GB or larger flash drive in an USB port on or connected to the Mac.
Open a Terminal application window.
Enter the command below to remove all extended attributes from the Ventoy live CD image (ISO) file. This will remove the quarantine placed on the file when it was downloaded.
xattr -c ~/Downloads/ventoy-1.1.05-livecd.isoUse the command below to determine the identifier for the USB flash drive. I my case, this was
disk2. If your identifier is different, the make the appropriate substitutions in the following commands.diskutil list externalEnter the commands below to copy the Ventoy live CD image (ISO) file to the flash drive. Note: Using
rdisk2instead ofdisk2usually results in a quicker copy.diskutil unmountdisk disk2 sudo dd if=$HOME/Downloads/ventoy-1.1.05-livecd.iso bs=1m of=/dev/rdisk2Enter the command below to eject the flash drive. Afterwards, you can remove the flash drive.
diskutil eject disk2Using the computer where Windows is to be installed, UEFI boot from the flash drive.
Note You will need to disable Secure Boot. When the following Grub menu appeared, I choose the first entry, which is the default.
Ventoy2Disk is loading completely into RAM disk. This allows the flash drive to be overwritten. In my case, to install to the same flash drive, I just needed to select "Install" button shown below, then the "OK" button in the following popups.
After installation to the flash drive has successfully completed, the following is displayed.
At this point, either manually shutdown the computer or reboot by closing the window. If you choose to reboot and are successful, then the following will appear.
Shutdown the computer by pressing the F5 key, then selecting "Power" and finally selecting "Halt".
Remove the flash drive.
Goto Microsoft's Download Windows 11 website and download the Windows 11 disk image (ISO) for x64 devices. In my case, the
Win11_24H2_English_x64.isofile was downloaded to myDownloadsfolder. If your file name is different, then make the appropriate substitutions when entering the commands below.Insert the same flash drive in an USB port on or connected to the Mac.
Use the same or a new Terminal application window to enter the following commands.
Enter the command below to remove all extended attributes from the Windows ISO file. This will remove the quarantine placed on the file when it was downloaded.
xattr -c ~/Downloads/Win11_24H2_English_x64.isoUse the command below to determine the identifier for the USB flash drive. I my case, this was
disk2. If your identifier is different, the make the appropriate substitutions in the following commands.diskutil list externalEnter the command below to copy the Windows ISO file to the ExFAT formatted volume named
Ventoyon the flash drive.cp ~/Downloads/Win11_24H2_English_x64.iso /Volumes/VentoyEnter the command below to eject the flash drive. Afterwards, you can remove the flash drive.
diskutil eject disk2If necessary, enroll key in MOK manager as described in this step.
Using the computer where Windows is to be installed, UEFI boot from the flash drive.
Note You should have Secure Boot enabled before UEFI booting from the flash drive. If you encounter the following display, select
OK, otherwise proceed to the step 7.The next display should appear as shown below. Before the timer expires, press any key.
Select
Enroll key from disk, as shown below.Select
VTOYEFI, as shown below.Select
ENROOL_THIS_KEY_IN_MOKMANAGER.cer, as shown below.Select
Continue, as shown below.Select
Yes, as shown below.Select
Reboot, as shown below.Install Windows 11.
If you have not already done so, UEFI boot the computer where Windows is to be installed from the flash drive.
Note You should have Secure Boot enabled before UEFI booting from the flash drive. When the display below appears, press the F5 key.
Select
Temporary Control Settings, as shown below.This answer assume Windows 11 is being installed on supported hardware. Normally, when booting from the Windows 11 installer, the following would be set to
0, as shown in the image below. You need to decided whether the following need to be set to0or1.Bypass CPU/TPM/SecureBoot check when installing Windows 11This allows includes bypassing the 4 GB RAM check.Bypass online account requirement when installing Windows 11
When finished, press the esckey twice.
Select
Win11_24H2_English_x64.iso, as shown below.Select
Boot in normal mode, as shown below.Note When message Press any key to boot from CD or DVD.appears, you may need to press any key.When the display shown below appears, proceed with the installation of Windows 11.
Example of Using the Terminal Window
Last login: Thu Mar 13 17:46:02 on ttys001
davidanderson@Davids-Mac ~ % xattr -c ~/Downloads/ventoy-1.1.05-livecd.iso
davidanderson@Davids-Mac ~ % diskutil list external
/dev/disk2 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: FDisk_partition_scheme *15.9 GB disk2
1: DOS_FAT_32 MYFLASHDRV 15.9 GB disk2s1
davidanderson@Davids-Mac ~ % diskutil unmountdisk disk2
Unmount of all volumes on disk2 was successful
davidanderson@Davids-Mac ~ % sudo dd if=$HOME/Downloads/ventoy-1.1.05-livecd.iso bs=1m of=/dev/rdisk2
186+1 records in
186+1 records out
195702784 bytes transferred in 4.038241 secs (48462383 bytes/sec)
davidanderson@Davids-Mac ~ % diskutil eject disk2
Disk disk2 ejected
davidanderson@Davids-Mac ~ % xattr -c ~/Downloads/Win11_24H2_English_x64.iso
davidanderson@Davids-Mac ~ % diskutil list external
/dev/disk2 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: FDisk_partition_scheme *15.9 GB disk2
1: Windows_NTFS Ventoy 15.8 GB disk2s1
2: 0xEF 33.6 MB disk2s2
davidanderson@Davids-Mac ~ % cp ~/Downloads/Win11_24H2_English_x64.iso /Volumes/Ventoy
davidanderson@Davids-Mac ~ % diskutil eject disk2
Disk disk2 ejected
davidanderson@Davids-Mac ~ %
My USB is 20GB, attempting to load the W11 .iso file and every time says I need more space.