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Archive for April, 2019

… on Creating UEFI Bootable USB for Windows 10 from Mac

Old PCs and Laptops will not allow to boot NTFS formatted USBs. Current Windows installers contain files larger than FAT32 can support. If we somehow break our Windows OS and we failed to make Recovery DVD/USB, here’s a way to make the Recovery USB manually. Make 2 partitions on USB that will allow olders boxes to boot it on the 1st FAT32 partition under UEFI and will allow you to copy larger install files on the other NTFS partition.

  • Prepare ISO Image
    • Download Windows ISO from their site –> `https://www.microsoft.com/en-us/software-download/windows10ISO` (10 being the latest version to date)
    • Mount ISO by clicking image on Mac and will be available on /Volumes/*
  • Prepare USB
    • Plug in USB on Mac and open up some terminal
    • Use `diskutil list` to verify the exact `/dev/diskn` of the USB
    • Make 2 partitions on USB (one FAT32 and the other NTFS) with `diskutil partitionDisk /dev/disk2 GPT MS-DOS BOOT 10g ExFAT WINDOWS10 0b` . In the end, these will also be mounted to `/Volumes/*`
  • Copy Files from ISO to USB
    • Copy smaller files to to FAT32 (BOOT) partition. Only required files to boot.
      • Copy all files from ISO except `sources` folder. Create a separate empty `sources` folder on this partition.
      • Copy `ISO:/sources/boot.wim` to the created `sources` folder
      • We just have the only necessary files to boot the USB
    • Copy all files including the bigger files for FAT32 to the NTFS partition
  • We have now a Recovery USB that will boot even in older boxes
    • Don’t forget to unmount the ISO and USB
posted by ninoy in Tips and have No Comments