So I am currently having a problem where I cannot boot from a USB and my computer automatically goes to the GRUB screen on startup. My computer came with Windows 10 and I added Ubuntu 17.04 on top of that. I use grub to choose which operating system I want on startup. Now, I want to get rid of my Ubuntu 17.04 partition and download a Ubuntu 16.04 in its place.
I already created a bootable drive and I changed my boot order in my BIOS menu to prioritize my USB first. Even though I have changed the boot order, my computer still goes to my GRUB menu on startup giving me the option of choosing my Windows or Ubuntu partitions.
My computer had no problem booting from a USB before since I have partitioned my hard drive the same way previously. I just cannot get to the USB boot menu anymore and am not sure of how to go about this.
How can I get my computer to boot from USB?