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I'm having this problem with my Toshiba L875-S7308 where I cannot boot my USB while in UEFI mode.

I have formatted the USB (tried MBR and GPT - same result), and restored the ISO using the Windows 7 USB/DVD Download Tool. When I try booting the USB, the laptop simply ignores it and continues booting Windows. I have tried changing the boot order, or manually selecting the USB with no positive result. It seems like it's not even recognizing it (it's not showing the USB's name in the boot menu).

However, when I try booting in CSM boot mode, the USB boots just fine. I tried installing Windows 10 in CSM then setting the boot mode back to UEFI mode, but I can't. I'm trying to dual-boot Windows 10 with Windows 8.1 (already installed) and I'm currently using GPT, so I need to format the drive to MBR but I don't want to go through that trouble.

I made sure that Fast Boot and Secure Boot are both disabled.

Any help would be greatly appreciated.

Moe
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6 Answers6

20

Two important points:

1: The Windows 7 USB/DVD Download Tool is not compatible with USB 3.0. To create a USB stick that is compatible with USB 3.0 using the native boot experience of the Windows 10 Technical Preview media (or Windows 8/Windows 8.1), use DiskPart to format the USB stick and set the partition to active, then copy all of the files from inside the ISO to the USB stick.

2: UEFI (CSM disabled) requires the USB stick to be formatted FAT32. If your stick is formatted NTFS, it would explain the behavior you have described.

WinOutreach2
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17

You will be able to boot in by using Rufus.

  1. Prepare the usb device in Rufus. Select GPT for UEFI only. Select FAT32. UEFI specs define FAT32 as mandatory. (Source)
  2. Set your bios to default settings. (This enables all uefi options and secure boot)

You can now install windows 10 in uefi mode.

Community
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Rahul
  • 603
3

Many of the hurdles that you might face when making a Windows installation USB drive are overcome with the right tool. The most versatile one at the moment is Easy2Boot. By following one of the tutorials out there, you can keep your USB drive (even large USB hard drives) formatted as NTFS, rather than limiting your options with FAT32. Even UEFI is possible. In my case, I have an NTFS-formatted USB 3.0 stick that I use to boot multiple installation ISOs in UEFI mode, and some ISOs are larger than 4 GB, which isn't possible with FAT32 formatting.

benJephunneh
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  • 2
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2

If the ISO is > than 4 Gb, rufus will use NTFS. So, in order to boot

  • disable secure boot in the bios
  • press f9 to change boot order
  • select your usb
  • DON'T PLUG THE USB ON THE USB 3.O PORTS, OTHERWISE IT WON'T WORK!
Francesco Taioli
  • 121
0

Rufus is an excellent tool to build a bootable USB with. It's not signed digitally, however, so you have to disable Secure Boot. (Source: explanation why GPL3 files are never digitally signed). The default settings in Rufus are fine, but for UEFI in non-mixed mode the Partition Scheme should be GPT.

Sometimes the Select/Download button functions a bit flaky in that the Open Dialog will sometimes not recognise an .iso file when selected. The trick is to copy the full path to the iso file in the File Name field. (Source:a description of and solution to the problem of Rufus not being able to recognise iso files)

Regarding the problem of OP, even if the BIOS has UEFI and legacy sources enabled (i.e. mixed mode) and Secure Boot disabled, Windows will still install fine from the USB disk on a GPT style drive. (I've just done and verified this myself).

Rufus screenshot with GPT setting

sandokanfirst
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-3

Disabled secure boot and UEFI mode and in legacy mode select first bootable device USB device or DVD and restart the system. Now you can install windows easily.

user944045
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