My Acer Aspire ES1-251 won't boot into USB.

[GavinoGav]

I have a bootable USB. My Acer Aspire ES1-251 won't boot into it. The USB drives are set to first priority. Help please!!!

 

[KittyFish62]

Try going in to the bios and going into "hard disk drives" or something similar instead of boot priority and changing it from there. Changing the priority doesn't do anything if the drive isn't selected as a hard disk drive.