Create a Windows 8 bootable USB stick from an ISO on Linux

I downloaded the Windows 8 ISO from https://www.microsoft.com/en-us/software-download/windows8ISO.

Format and prepare the USB flash drive

# fdisk /dev/sdx

• o new DOS disklabel
• n new partition
• [default] partition type
• [default] partition number
• [default] first sector
• +8GiB last sector, since the ISO is around 4GiB
• CONDITIONAL: if notified about an existing signature, confirm changes with Y
• t to select partition type code
• c for FAT32 (LBA)
• a to make bootable
• w to write changes and exit

The output of the p command in fdisk should now read something similar to:

# fdisk -l /dev/sdx1
Disk /dev/sdx: 149.5 GiB, 160041885696 bytes, 312581808 sectors
Disk model: [redacted]
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 33553920 bytes
Disklabel type: dos
Disk identifier: 0x12345678

Device     Boot Start      End  Sectors Size Id Type
/dev/sdx1  *    65535 10551134 10485600   5G  c FAT32 (LBA)

Create NTFS file system. Use -f for fast format, to really speed things up. (NTFS disk tools can be installed from the AUR as ntfs-3g)

# mkfs.ntfs -f /dev/sdx1

Mount both the ISO and the NTFS partition

# mkdir -p /mnt/disk /mnt/loop
# mount /dev/sdx1 /mnt/disk
# mount -o loop ~/downloads/Win8.1_Pro_N_EnglishInternational_x64.iso /mnt/loop

Copy the files from the loop device (ISO) to the USB flash drive NTFS partition. I like to use rsync for its progress output, but you might as well use cp -av.

# cp -av /mnt/loop/* /mnt/disk/

Don’t mind Operation not permitted messages when attempting to set file permissions. This is expected with the FAT32 filesystem.

Synchronise cached writes and unmount the disk

# sync /dev/sdx
# unmount /mnt/disk

References

• https://thornelabs.net/posts/create-a-bootable-windows-7-or-10-usb-drive-in-linux.html
• https://itsfoss.com/bootable-windows-usb-linux/