Zorin OS, can't boot from USB

I recently installed Zorin OS on my Lenovo Yoga 2. I completely got rid of Windows and am not dual booting. I am now trying to get back to Windows 10. I created a Windows 10 USB drive, but I can't get the computer to boot from it. When I change the UEFI boot order, it still boots into Zorin, and when I go back to the UEFI, it has changed the boot order back. I also created another Zorin USB drive, thinking I would boot from it, then format the Zorin partition so it would have to boot from USB. Same thing, it just won't boot from USB. Is there a way to trigger booting from USB from within Zorin? If not, any ideas on how to get rid of Zorin some other way?