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This. You could also check for a setting called "Windows 8/10 Features" or something similar in the BIOS, as that sometimes controls Secure Boot on older boards. Good luck!

I had the same problem. On my ASUS board, I had to disable the CSM setting completely before the Secure Boot option even became visible.

This happened to me. I got that exact error and had to go into the BIOS to switch my drive from RAID to AHCI mode to get it to boot.

Same here. Yeah, that's a good call. Also, double-check your disk partition style—it needs to be GPT, not MBR, for the install to work.