More info, please. Also, search Google, if you know what question you really want to ask.
I created a Linux Mint stick a few years back when the OS partition of my HDD failed. The rest of the drive was fine and I was able to safely relocate all of my files!
Anyway, Google your make of PC for how to enter the UEFI (BIOS). All I needed to do is continually tap F8 or something while booting to get to my UEFI screen (BIOS) and move the USB port to the top of the boot list.
Actually, I think I might have had to delete all other boot options, since I seem to recall it trying to boot to Windows, even with the USB port at the top of the list...YMMV