Hi, It was a while ago now, but I think you have to boot into BIOS (might be at 90 degrees to keyboard!)- then go to the last BIOS tab - something like "Save and Exit" and scroll down to "Boot Override" and on a good day the USB will be listed - select it. Again, from memory, if USB not showing, there might be some other BIOS settings to tweak to do with Secure Boot, USB boot, Legacy boot that are required. I no longer have one to refer to.