Unable to boot Windows 8.1 UEFI USB key on XPS 13 2015

I have an XPS 13 Developer edition on witch I try to install Windows 8.1

I have already done that on others computer always with success. But I am unable to do so with this XPS.

I use Rufus to create bootable usb key, with the followings options :

• GPT partition scheme for UEFI


• FAT32 file system

I tried with 2 different Windows 8.1 iso and two different usb key.

My UEFI configuration is the following :

• UEFI with secure boot disabled


• Legacy Option Roms enabled

When I boot my XPS and press "F12" the usb key is never displayed in the BIOS menu...

What am I missing ?
Thanks in advance for your help...

Answer

I finally found a solution by changing some setting in the BIOS configuration :

In "Boot Sequence" > "Add boot option".
My USB key showed up as : "PciRoot(0x0)/Pci(0x14,0x0)/USB....".

Then in "File name" I had to browse in my USB key and select "File System : FS1".

I saved and was finally able to boot my Windows key.

I hope this will help someone in the future.