I have just purchased Dell XPS-13 9343 (upgraded to windows 10) and I am not able to boot this laptop from my USB 3.0 which have Ubuntu 14.04 installed on it.
I am able to boot my Dell Latitude and HP Elite Book from same Ubuntu USB. I don't know what to do. After putting BIOS In legacy mode I can see external USB in boot option (by pressing F12) but when chosen and pressing Enter screen appears that booting has been failed.
You do not need to switch to legacy mode to install Ubuntu.
It seems that the bootable USB drive was not created properly.
Try to recreate it using this guide.
When it is done, put your BIOS back in UEFI mode (secure boot disabled). Insert the USB stick, boot your XPS 13 and hit F12. You should now see the bootable Ubuntu entry.
If this still does not work, try to recreate it using Rufus with the following settings :
Hope this helped.
I have exactly the same problem.
The issue is with Dell XPS 9343 early 2015 model (one of the first ones). I have two Dell XPS 9343 laptops but one of them is 4 months younger and all my usb sticks works fine in there.
However, the older one does not see any usb sticks and it's impossible to boot anything.
So, I have two usb sticks: 1st one with Ubuntu 16 live edition 2nd one with Windows 10 installer
I haven't managed yet to run Ubuntu one but the one with Windows I was able to run by setting up UEFI bios in the following way:
That's it.
This is only applicable to Dell XPS 9343 early 2015 model.
As said above, younger generations of this have this issue fixed and you can see every bootable USB stick without changing UEFI settings.
