You can toggle the active flag with diskpart (and third party partition apps). To make the flash drive bootable ONLY in UEFI mode, skip step 10 of the procedure which marks the USB flash drive partition as active.
The flash drive created above will be bootable with both legacy BIOS and UEFI. To format the partition, type format fs=fat32 quick, and then click ENTER.įor step 12 of the above procedure you will mount the downloaded Windows 10 ISO file and just copy all the files and folders from the mounted ISO file to the USB flash drive. Note to format the partition on the flash drive as FAT32 to make it compatible with both legacy BIOS and UEFI:ĩ. This is how to prepare a USB flash drive for booting. What are you attempting to install Windows 10 from? In order to install Windows 10 in UEFI mode onto a GPT partitioned drive, the Windows 10 installation media must be booting in UEFI mode as well. I do not know if that applies to your ASUS laptop or not. The hard drive had to remain MBR partitioned, though, and the OS had to boot in legacy BIOS mode.
It had limited support for UEFI booting in that it would only boot the HP support tools as UEFI. I had an HP laptop that had what I called hybrid UEFI.