This Answer is assuming that your laptop is using UEFI
.
UEFI
is the replacement for BIOS
. Which provides an abstraction between Operating System and Hardware and is used to boot up your Computer.
Every new computer ships with UEFI as default.
A Bit of Theory
When booting up your computer the EFI System searches the active drives that are connected to your Computer for an executable in the folder /EFI/BOOT
.
If such an executable is found the drive is considered to be bootable.
The BIOS
on the other assumed that your boot manager is stored in the first section of the hard drive.
What's Happening
UNetBootin
configures your USB Stick in the old MBR
Style. (Which is that the first section contains the boot manager).
Your UEFI
now searches the USB Stick for the /EFI/BOOT/BOOTx64.EFI
(or similar) executable and obviously can't find it so it continues, according to the boot order
to search the next defined device until it finds one which contains said executable. This is why you can't boot from your USB Stick.
Fixing the Issue
There are two ways to fix your issue.
1:
In order to keep compatibility legacy mode
has been built into most EFI Systems which allow to boot from an MBR
Partitioned drive. In order to activate legacy mode
you will first have to disable Secure Boot
because that will prevent you from Activating legacy mode
and then you will have to activate legacy mode
.
These Settings can be found in your UEFI
Boot Configuration (or BIOS) under System Configuration
and or Security
.
2:
Nowadays most Linux Systems support UEFI
Boot. To make sure open your ISO (for Example with Virtual Clone Drive
and check that the folder /boot/efi
exists. If it does all you have to do is to format your drive to FAT32
and extract the content of the ISO into the root folder of the USB Stick (Copy Paste from Mounted Image or extract with WinRar). note: you still have to disable Secure Boot
I hope my answer has shed some light onto the issue.