I'm trying to make bootable usb from win10 iso (should be legal, I got in PC magazine). The iso is OK, it works boots in virtual box.
I tried fedora "media writer", ubuntu "disks" and good old "dd"
sudo dd bs=4M if=/tmp/win10.iso of=/dev/sda conv=fdatasync
and while that thing says it's bootable:
/dev/sda: ISO 9660 CD-ROM filesystem data 'CHIPSPEC_WIN10_II' (bootable)
it cannot be booted on none of mine computers, all linux based(meaning I cannot use any windows app to write image or do any investigation there). I did not use windows for years and did not install them even longer. Does newest windows require something special from bios? Is uefi mandatory? Is secureboot mandatory? Or what can be the issue?
Best Answer
It says the ISO-9660 CD image is bootable. However, that uses a different mechanism from "regular" disks (HDDs/USBs) – the BIOS-compatible boot code isn't located in sector 0, nor is the UEFI-compatible partition table.
The Linux ISOs that you've used in the past have been specially prepared using isohybrid to be bootable both as CD images and as fixed disk images. Windows ISOs are not – they're meant purely for CDs/DVDs, so you'll need additional tools.
For UEFI, this in theory should be simple (just extract all files onto a FAT32-formatted disk, using DISM to split install.wim if necessary). For BIOS, you'll additionally need ms-sys to write Windows-compatible bootsectors.