I agree, let me second that to confirm what other's have said already.
Enter the bios, on some computers thats the DEL key, on other computers its the F2 key.
SECURE BOOT and disable
In the boot order, tell it the first drive you want to boot from is USB drive. Set the internal hard drive to be 2nd on the list to boot from.
SAVE and exit, which is F10 on my computer, but could be different from yours.
Make sure to hold the
LEFT SHIFT key while in the boot sequence, this should force you to enter the boot menu on the Zorin ISO.
If you DON'T have Nvidia GPU, then select option one to install.
If you do have an Nvidia GPU, select Nvidia install version from the list, which is at the bottom.
If you have an Nvidia GPU, but you have issues booting into the ISO with the Nvidia option, then do the first option.
I say this cause Nvidia drivers can always be installed later down the line, after the OS has been installed. Again, only relevent if you have an Nvidia GPU.