Difficult installation of Zorin OS on HP Spectre360

I have the same sort of issue.
I tried Zorin free live several times on my Lenovo PC without problems. I decided to purchase the Pro version, but it screwed the PC up to the point where I had to reformat reinstall W10 etc etc - a pain.
I decided today to install the free version on my HP Spectre360 laptop, I went into the American Megatrends BIOS and made sure it was set to boot first from the USB - and it just doesn't work.
I have set the BIOS to many different settings and finally screwed the computer so had to go through the Wretched Micro$oft authentication (which took hours since I have changed passwords several times....)
I cannot see any way of getting the Zorin USB to boot: it worked on my PC but want to use it for a while on the Spectre.