Cannot Boot from USB

[firenice03]

I have bought a Dell Inspiron laptop with Ubuntu 14.04 already loaded (and booted via UEFI).  I want to install LL as the primary OS, but the machine will not boot from the live USB.  I have tried both LL3.0 and LL2.8.

I have changed the boot mode from UEFI to Legacy in the BIOS and set USB as the first boot priority.  It appears to be booting normally into LL, displaying the LL feather screen, but it then opens a live version of Ubuntu 14.04 (not the installed version that I have modified).

I have run Boot-Repair and allowed it to make the recommended repair, without venturing in to the advanced options where I am out of my depth.  A copy of the text report produced after the repair is attached.  Boot-Repair also displayed the following message:
"The boot files of [The OS now in use - Ubuntu 14.04.4 LTS] are far from the start of the disk. Your BIOS may not detect them. You may want to retry after creating a /boot partition (EXT4, >200MB, start of the disk). This can be performed via tools such as gParted. Then select this partition via the [Separate /boot partition:] option of [Boot Repair]."

Sounds like the USB tries to boot but then fails and reverts to a Ubuntu Safe Mode (installed OS) of sorts..
Check if BIOS has a secure boot option as well and disable that..

Boot repair more than likely will not fix anything as LL is not installed (just the original OS's on the disk).

Once the LL live environment boots, there are a few caveats to installing. Make sure you read up by searching UEFI from the main forum as well as glancing the manual.

Let us know it it goes