I have done this a hundred times but I am not getting my USB to boot from the drive. I use Rufus to make the bootable drive from a good bootable .iso. I format it with MBR partition scheme for bios or uefi. My computer has secure boot bios..so I disable secure boot and enable legacy in bios. The drive is formatted NTFS because Fat32 can't have a .wim over 4GB...This bootable does. Why doesn't my USB flash drive show up in the boot menu? What am I doing wrong? It works if I make it for UEFI when I'm doing a Wind 10 GPT scheme and formatting fat32?
Trial and error I figured it out. I had to select the option from Rufus that says "MBR partition scheme for UEFI" The first option says for UEFI as well so why didn't it work?
I been using Rufus tools and never had problem, All I use FAT32 8GB or less on USB Flash.. works for me.
I just format the USB FAT32 and extract the iso to it's root. It should work when you split the install.wim into more smaller install.swm's (<4GB), to fit FAT32 max. filesize and follow this guide https://forums.mydigitallife.net/threads/fixing-a-image-for-uefi.75244/#post-1375604 Addition: Do you use a kabylake/ryzen based system? Be sure you integrate the proper USB3.x drivers in boot.wim (both indices), to be able to boot the USB install medium.
if its an hp you need to probably also do the uefi diagnostics on usb if trying to do uefi usb.. it was only way i could get w7x64 or 8 uefi on the hp compaq 2000 if mbr in rufus check the 0x80 bios in advanced.