Windows Upgrade Help and more

Thanks! I turned off CSM like you said, but now my computer won't boot at all and just shows a black screen. What do I do?

I’m trying to upgrade my Windows 10 PC to Windows 11, but the PC Health Check tool says my system doesn’t support Secure Boot. I’ve checked my BIOS (UEFI) and it *is* enabled. I keep getting the error "This PC must support Secure Boot" with code 0x80070002. Has anyone else hit this wall? I’m not ...